I don't think it's a matter of frames changing, more a matter of moves having to go through standing animation frames before coming out.
So if you block a move crouching then retaliate with s1, you have to first stand (which may take 1-2 frames) then the s1 comes out, much like there is 1 frame after letting go of block before normals come out.
I was seeking clarification on whether or not reversals and crouching normals have this as well.
Probably the easiest way to test this is to find a move that's between -7 and -10 and test if the move can be punished by a 6-9 frame move (respectively) from both crouch and standing. It'd have to be a move that hits mid.