I see a lot of comments saying LeChuck seems too goofy, but I always find that LeChuck is at his best when he has goofy moments that disarm us and then a sudden shift to scary and creepy. LeChuck's Revenge was probably the closest to seeing a purely serious and sadistic LeChuck, followed closely by Tales Episode 5, but I think it can work better when you don't expect it. The idea that we can laugh at this guy, but then remember in the next scene that he kills and tortures people, forms pacts with demon netherworlds, becomes a demon himself, and conducts satanic rituals, has always been one of my core experiences with the series.
The trailer implies that LeChuck will very much still have plenty of dark moments and remain a legitimate threat, which I think is the more important piece. I don't mind him having goofy moments, so long as he's still a legitimate threat. I would also say that I don't view LeChuck himself as being really goofy here; it's just the context of the scene.
The scenes that will showcase his malice will be when to really judge if this version is too goofy or not, but so far, I really like the voice and it fits the character well in my opinion.