Listening to the new GameXplain discussion has me doubting the leak unfortunately. Originally it seemed possible that 'insiders' had conflicting information because that info was out of date (Gematsu information) but with Jon and his otter image clearly indicating he knew the direct was coming, his source seems to still be active. If he's still demonstrating predictive abilities, it's less reasonable to write off his other predictions given his track record, even if he's not sharing his evidence beyond 'We had reason to believe it was fake.'
I'm sure they have good reason they feel they can't, but I wish they could just say why they don't believe the grinch leak. It's easy to infer they have a source either confirming or deconfirming at least one character that conflicts with the banner, but then they go on to say that speculation will be totally spoiler free. Feels like they're being disingenuous.