If MK10's breaker system is going to be just an iteration on the MK9 breaker system, using the old model would be fine. Overall they really just need to tweak meter gain values and that is it.
That being said, there is much that can be improved on in the meter usage department such as an "alpha-counter"/"shadow counter" type move, block button parries, universal armor moves, and/or push-blocks (I can take/leave PBs overall for MK10 but it's an option). Buffing X-rays would be cool as well, as using a raw X-ray should take 40-50% easy for every character. There should be greater risk reward for going all in with them.
On the other hand, and I was talking about this in some other thread, another route they could take is divorcing the breakers from the traditional meter bar all together. If breakers/push-blocks/"alpha-counters" (all/any universal defensive moves) were all tied to a universal block/guard gauge, that would take breakers and level the playing field across the board for all characters. Traditional meter gain can be the same (performing/whiffing special moves to gain meter, getting your opponent to block your attacks, etc.), but the block gauge would be one that starts low and fills over time automatically. Blocking attacks could decrease the meter, parries would decrease meter but negate block stun, and taking a hit could gain meter or have no effect at all (all this would depends on balance needs).
If a system like this were in place, in my mind at least this would give no distinct advantage to any specific character in terms of defensive options, but only reward the player who uses their resources the smartest. It would also be something new and fresh, and could also be pretty fun!