Battery weight, harvesting allowed per lap, and deployment per lap are all controlled by the regs. They aren't likely to just allow more energy stores when the regs intended to cause a reset in...
I think inherently, they are trying to reduce bulk by that limit. If the same battery dimensions can hold twice as much at the same weight, the FIA may allow an increase in the power limit....
The battery capacity is limited to 9 MJ. Development might make them smaller and/or lighter but it won't make them last longer unless the energy limit is increased.

I'm still confused with this project. Many people have said it resembles a Porsche Macan, which says one of four things is happening. a) If it is to be a Porsche Macan, Porsche will be involved....
WRC mainclass from 2027