Cliff can correct me, but the main benefit for Fractal here is cost and porting effort required by having a directly Axe-Fx 3 compatible platform.
If TI is now offering DSPs that are more power efficient, cost effective and more straightforward to integrate, then future Fractal products could move to using only TI processors instead of the mix of TI and Analog Devices. Axe-Fx IV is likely to use the newer TI C77x cores, but "FM4" and "FM10" are still a mystery, if those products happen in the first place.
Cliff did make a comment
here about the Analog Devices SC594. While this was in regard to a potential future Line6 product, I'm sure Fractal has considered the same processor for their future FM series as well. Afaik the SC594 should be about as powerful as the FM9 but with a single chip. So you could think of getting a "FM4" that has the same DSP capabilities as the FM9 - basically "more than enough for 99% of guitarists out there."
Fractal could potentially make just a single floor unit for next gen, finally realizing the idea of the modular system that the FM3+FC6/12 can be, but without the DSP compromises the FM3 makes.
I'd love to see a "FM0" brain type device where you can connect a variety of external peripherals. The LuminiteFx Graviton M1 MIDI controller is a great example of that sort of product line, and a direction I'd love to see on future modelers. Every peripheral works wirelessly without issue, and you can make it as complicated or as compact as you want. For gig-proof security you can still connect the footswitches with a wired connection too.