Battery life can't be encompassed as just one single issue, in a single specific piece of software, nor can it be magically cured with one piece of software either. Not only do we need hardware solutions to accomplish more power efficient chips (which we've gotten through the years) and microcontrollers for all the various devices in your system, but accompanying work in software. This ranges from the kernel on power management, CPU schedulers, etc. to optimizing libraries and user-facing software. None of it is easy, and none of it can be solved with TLP.
TLP is good really at two things:
- Turning stuff off, even when you don't want it.
- Downclocking or limiting max P-states.
Most of the stuff TLP claims it can do like GPU power management is already done by the kernel, tlp is just typically manipulating the behavior to ensure it's always happening (see downclocking).
So will Solus receive better power management? Yea, we always do. Will it necessarily affect your device depending on what is providing those optimizations? Not necessarily. Do I still want to replace TLP? Sure, even out of selfish reasons I'd want to improve battery life (less time my laptop has to be on the charger and more time I can be out-of-office with it the better!) but there are simply vastly higher priority items we need to work on first.