The author's hypothesis is undermined at two points: by their insistence on making it as oblique as possible (thanks, I suppose, to UnHerd's editorial predilection towards dressing up conservative culture war talking points) and by the fact that none of their "villains" are actually villains. At best, they're morally flawed or challenging characters, producing narrative complexities that Disney (or whoever) lazily expounds on. That, not the darn liberals, is why we get therapy-Joker.
Commercial media is doing what it's always done: identified lucrative properties and milked them until the audience either becomes tired or cynical. They've been doing it to Roald Dahl for half a century now! But to (again, obliquely) identify the BFG as a villain reeks of argumentative desperation. Come back when they try to rehabilitate Miss Trunchbull[1].