I'm glad they finally addressed it now instead of just putting it off as long as they could.
A studio like Naughty Dog should know better about releasing 60fps footage if they aren't positive that's what they're going for in the final game. I hate being BS'd by game companies and seeing something like that from my favorite studio is a severely disheartening. It also created an unnecessary round of negative PR for the game. Everyone would have just assumed Uncharted 4 was going to aim for 30 if that video hadn't come out. Had the E3 trailer been 30, no added questions would be asked. Whether it just be a matter of overambition of cockiness, they shouldn't have shown footage at 60 before they knew what the final target would be. A statement of a 60fps target is less of a promise than actual, tangible, real time footage.
That said, this statement at least sounds like they're considering dropping the target for gameplay reasons versus purely visuals. I've said for a long time that the 60/30 debate isn't purely a graphics versus gameplay argument. Things like physics, destruction, AI, and level design could all make 60 be out of the question. Many of those things wouldn't drop it down to 30 either, just make 60 problematic, so we could probably expect noticeable visual enhancements (high quality object motion blur please) as well.
Naughty Dog's games last gen also had more input lag than most 30fps titles. It wasn't too noticeable due to how they handled animation so if the final game does end up 30fps, there are ways for them to improve controller response from the previous games in the series. Seeing something like 60fps input polling and simulation with rendering at 30 would feel much snappier than the previous games.
Running at 37 right now does bode well for final performance whatever it ends up being but until I hear otherwise, I'm just going to operate under a 30fps assumption.