A) they know it's fake and have seen footage or have info of characters mia
B) they think/know it's real, and are fully on board the "don't want to ruin the surprise" hence the comment of "not wanting to give this more exposure"
C) they think or have strong reason to think it's fake, and don't to waste time getting people excited about it
D) they think/know it's real, and are afraid to talk on the record for fear of being blackballed by Nintendo
A good summary, but I would argue that if A and C are true, then GameExplain has nothing to lose as a channel. They get to do what they usually do and rip apart a fake leak with their usual thorough analysis and get loads of hits on their channel covering the biggest leak to come out since the NX days. Why the silence guys?
And I'll just add they can do this without exposing anything they know, there's enough teamfake evidence out there without revealing any confidential details about the game.