the gaiman allegations are pretty unsurprising to me, and their specific details dovetail neatly with the vibe he's given off for decades. his fanbase is devoted in a very particular way, and his kindly solicitousness has always made them feel a part of his world--a situation ripe for abuse.
it's his public persona that's the problem, although i'd say that it has somewhat infused his writing as of late, which is why it's become progressively less appealing to me.
I don't think there's anything in Gaiman's writing that's a clear red flag for being a predator, but to me his style got lazier and more self-important as he settled into his role as god-emperor of the fantasy goths. an uncritical following that he accepted happily.