Ruth2/Roth2 project leader Austin Tate posted on his blog today that a whole new free and open-source mesh body for OpenSim and Second Life is being worked on. Ada Radius seems to have completed the mesh already.
https://blog.inf.ed.ac.uk/atate/2023/09/13/max-new-open-source-mesh-avatar/
It's named Max, and the female and male variants are named Maxine and Maxwell respectively. I'm not sure if Max will only be a common base for two separate mesh bodies, or if it can be switched between Maxine and Maxwell. The latter would mean interesting new possibilities clothes-wise.
Speaking of which, one goal is to have a much more usable dev kit that'll make creating mesh clothes for Max easier than for Ruth2 and Roth2. I hope this will be the case because Max will start from zero clothes-wise, and compatibility with mesh clothes for the system body will have to be re-evaluated.
As of now, nothing has been released to the public yet except for that blog post. But stay tuned.