I'm surprised they're replacing the FT. My DD is a weak front tumbler and it took awhile to get her to figure out how to front tuck nicely.
Perhaps they're trying to make more of a difference between L5 & L6?
If my DD was never forced to do that FT at a young age in compulsories, I think she would have been so screwed for front tumbling in optionals. She's had beautiful ariels her whole life and I'm sure would have scored much higher doing that instead, but forcing her to work on/perfect the front tuck was very important. Maybe they are hoping that will get worked on in L6 like you said though.