Michael Bay and Platinum Dunes are clearly enjoying the amount of free publicity the off-the-cuff "they're Aliens now!" stuff has gotten their previously not-much-commented-upon TMNT reboot; otherwise there'd have been more "damage control." But early on, BadassDigest's Devin Faraci posited that maybe this was all a huge misunderstanding and it was really in reference to a "back to the source" take re: the original Mirage books, where the "Mutagen Ooze" that created the good guys came from T.C.R.I. Labs (T.G.R.I. in the movies, nonexistant in the show) which was actually a front for aliens called Utroms, who in turn inspired "Krang" in the animated series. Looks like he might've called it...
In an interview with Collider, director Johnathan Liebesman offered the following:
"Look, it’s so funny—if everyone was such a die-hard fan, they would know that the TCRI canisters where the ooze comes from. That is alien ooze."
Well, okay then. This still doesn't help the broader issues - re: that Platinum Dunes is a terrible studio and Liebesman's thus-far sole screen effort ("Titans" isn't out yet) "Battle LA" was horrible - but it's definitely less head-scratching. And while it's currently en-vogue for fans to dismiss the 80s series out of hand (even though it's demonstably impossible for everyone who says they were fans of the Mirage comics first to really have been) I'd bet good money that if the follow-up announcement is "Oh, BTW... KRANG!" the "buzz" turns around right-quick.