I imagine if Capcom patched the game and said they reduced SFV's input lag to SF4 levels but actually didn't do anything people would post about how much more responsive the game feels until someone officially tested it. Sure, I'd like it if another frame was removed but I doubt the impact it would have is all that important.
My dad's friend who works with a guy who works with a relative wat capcom says the frame lag has actually been 0 the whole time and we all just suck.