IANAL but I would assume that, since they're moving from "minecraft.fandom.com" to "minecraft.wiki", it should be no more infringing than what they previously had, unless second-level domain names are subject to more scrutiny than third-level domain names. And if that's the case, then I would expect that the infringing party would be their domain name registrar, for being the one to sell them the hypothetically infringing name (which isn't to say that the operators of the server couldn't be subject to trademark claims for other reasons unrelated to the domain name).
