I haven't watched the video, so I might be wrong. Wouldn't be surprised if I was. But I think a lot of the ending variety or at least part of it is going to depend on where your companions/origin characters end up. Dead? Living? Doing something here. Or somewhere else.
Yeah but we're talking 17000 ending variations. He also specifically asked how many main endings there were and they didn't know. We're still comfortably looking at BG3 having the largest amount of possible endings in an RPG even just on the number of main ending without going into minute differences like which companions lived through the playthrough and so on.