The flopping rule is basically irrelevant. There are tons of rules that aren't ever enforced; as far as I'm concerned those are empty words until it gets consistently called.

The coach's challenge change however is HUGE. Whether it's gonna be good or bad, I can't say. Challenges get denied all the time, so I doubt this will actually make the coaches more prone to calling it, but it might make it so that we see early obvious challenges more often since coaches often don't challenge obvious calls early in the game because they prefer to keep the challenge for the 4th quarter.