Hmm...I don't know. 74's been slipping recently. Martin, I believe, is far more credible when it comes to Disney rumors. Also, something about 74's post doesn't add up, even by Disney exec logic.
I honestly can't stand his persona, he posts like he's some big shot, like he has something to prove. Grates on my nerves. Nonetheless, I do recognize he has a track record, but he's not perfect as he so often claims to be.
Martin has conflicting info (thus far) and so does another insider I've been in chats with, for what it's worth.
(^ Regarding GotG placement)
As to the Avengers ride, I think 74 was just guessing about potential possibilities, not hinting that something was actually in development. But, that's my interpretation.