Why would Mario Kart 8 be playable when it releases 2 weeks before E3?

I'm calling their bluff.

Gears of War 4 playable/Uncharted 4 tech demo makes absolutely no sense given what we know about both games (one was only recently transferred to Black Tusk, halting development of their previous game; the other was scheduled for 2014 but likely pushed back to 2015.

Also, this would be the lamest E3 if true. No surprises, except for Xenogears: Origins which reads like fanboy-written nonsense disregarding IP ownership.

Wouldn't it be logical for Sony to have Assassin's Creed: Unity and The Last of Us Remastered?

Ubi has their own conference. 

It's common for companies to bring recently released games to these trade shows, so that's about the least stupid thing on this very stupid list. In fact, it's the lack of any other released games (like Titanfall) that stands out.

Acquisition of an IP, especially between two publicly traded companies, would have been reported on by multiple game news outlets.  That's not something that can be kept secret.  If not immediately, both companies would've had to announce it during their quarterly earnings calls anyway.   

Castlevania Symphony of the Night 2, why do trolls do this to me?

If Symphony of the Night 2 comes true I would buy almost everyone on VGChartz a WiiU...

... if I had the money.

Yeah, it definitely wouldn't have gone unnoticed. I remember how excited all the gaming sites got over the false story about Nintendo co-owning Fatal Frame.

Gears of War 4 gameplay but only a "tech demo" for Halo 5? That sound extremely unlikely.