From the MuggleNet podcast page:
In this episode, Katy and John do a deep dive into the symbolism and transformative power of J.K. Rowling’s work. First, John describes the concept of literary alchemy and how literature can effect an alchemical transformation on readers. Then, special guest Evan Willis (University of Dallas) explains how Renaissance alchemical symbolism intertwines with classical myth in Harry Potter and Cormoran Strike. From the Orestes myth to Castor and Pollux and Leda and the swan, we learn about the well of myths Rowling draws from in her literary creations. Willis particularly directs us to the importance of a Hermes/Mercury figure to serve as the invisible force behind the uniting of opposites. Who is this mysterious figure in Harry Potter and in the Strike books? Listen to find out the surprising answers!
Does literary alchemy work on us the same way when we’re watching films? We tackle this issue in light of the classical references in the Fantastic Beastsmovies. We also try to predict the next developments in Strike and Fantastic Beasts based on our understanding of the deep mythic context in both series. We’ll help you sort out the stories of Leta and Theseus, Dumbledore and Grindelwald, Cormoran and Robin, and Shanker and Rokeby and anticipate where they might be headed.
Brad Bellows told us, in
While the predominant symbolism of the story is white horses, which occur so frequently that Strike remarks on it and Billy Knight laughs about it (pp 394, 496), white swans occur often enough, not only as the story’s framing brackets but in references to individual birds on signs (see Robin’s noting and overlooking the Swan pub sign on pp 56 and 166), that we are obliged to consider their meaning beyond markers of Leda mythology in which the books are set. Swans, as you might expect in a Rowling novel, have an alchemical meaning as well, one that we will explore after the jump.
Crimes of Grindelwald, in its climactic scene, has Grindelwald presenting a prophecy of World War Two. This, I suggest, was one of the largest plot twists the movie provided, in that it leads us to consider Grindelwald’s motivations as good, but his means to achieve them as evil.
However, as far as I can find, there is in the entire text only one reference to the existence of World War Two, in a brief comment at the opening of Goblet of Fire, in which Frank Bryce is described as having “come back from the war with a very stiff leg and a great dislike of crowds and loud noises…,” (Ch. 1). This is our only source that World War Two happened in this alternate world in which magic exists, and is a fairly vague reference at that. It could be possible, with minimal damage to existing text (less drastic than certain already existing plot elements), to have World War Two never occur in this alternate muggle history.
That said, I think all that this shows is that we, as audience, have been left seeing the Second World War as a merely possible, not historically guaranteed, event. We know as much about this version of the 1940s as Newt and Grindelwald themselves do. However, World War Two not having happened would still be something of a plot twist, and so the following analysis is going to be relatively independent of whether or not it did.
With the war with Voldemort, the Death Eater’s goal was clearly one of wizard supremacy over the muggle population as an end in itself. At least publically, Grindelwald presents the argument that the muggle population is prophesied to begin another world war and that the only way to stop this is to provide muggles magical help, in the form of rulership by the wizarding population. Wizarding supremacy is for the muggles’ benefit, so goes Grindelwald’s argument (borrowed from Dumbledore’s letter to him in Deathly Hallows Ch. 18), in that being in the magical community places one in an enlightened elite who can solve the muggle’s problems. 
Thus, wizarding supremacy is portrayed as a means to the “greater good” of progressive and enlightened policies (and thus, incidentally but not in itself, it appeals to those like Rosier who desire wizarding supremacy for its own sake). And Rowling goes out of her way to present about as clear an enlightened and progressive “greater good” as one could ask for: stopping World War Two from ever having happened. (This reminds one of the old moral dilemma that asks “If you could go back in time and kill Hitler as a baby, would you?” Part of the beauty of the contingency of the Second World War in this universe is that you don’t know what is going to be chosen.) 
Dumbledore’s group is opposed to the tyrannical wielding of power to achieve those progressive ends. Thus, this film reveals the battle between Grindelwald and Dumbledore to be one over means, not ends. Both favor progressive policy (e.g. allowing muggles and wizards to intermarry), but Grindelwald wishes to accomplish this by the conquest of the muggles, Dumbledore will not use such means. It is precisely on account of the parallelism that we had been led to expect with the sides of World War Two (i.e. Grindelwald as wizard-Hitler) that this new formulation is such a remarkable plot twist.
This distinction is foreshadowed by prior elements of the plot. At the opposite end of the movie, we see Queenie’s willingness to use magical power to attempt to force Jacob to marry her counter to the regressive laws present under MACUSA. This alone, I think, is enough to demonstrate the natural agreement of her views with Grindelwald’s: progressive ends, tyrannical means. Newt here, in disenchanting Jacob, shows his support for enlightened ends, in that he truly desires their marriage, but denies the validity of the means Queenie attempted to use. 
Beyond this, there is the treatment of prophecy by both sides. Grindelwald, believing that the prophecy will be fulfilled unless stopped, is trying to use whatever means necessary to keep it from happening. It is entirely possible that he, like Voldemort, will be so eager to stop the prophecy from happening that he causes the prophecy to be fulfilled. Thus, I expect World War Two will happen, but largely because Grindelwald attempted to stop it. Part of the value of us not knowing whether the prophecy will be fulfilled is that we can side with Dumbledore and Newt, not willing to step beyond what is right even to stop a terrible prophecy, with the possibility that by thus refraining one might keep it from being fulfilled. This may be the origin of Dumbledore’s insistence that prophecy’s power is only over those who believe it to be true, who consequently wield power rather than relying upon love (Half-Blood Prince, Ch. 23).
The story begins — its first words — at the Cunliffe wedding reception with a photographer trying to get a picture of the newlyweds that includes two swans in the pond behind them. The swans stubbornly refuse to come together, but, as soon as Robin rises to separate herself from Matt (with the intention of looking for Cormoran), they swim side by side. The clueless father of the groom observes, “You’d think the buggers were doing it on purpose” (p 3).