So moving away from GHA will not make self-hosted runners free, they’ll move into a different pricing structure that may or may not be beneficial.
And I think charging for self-hosted runners is actually fine. They’re not free for the provider either - log aggregation, caching of artifacts, runner scheduling, implementing the runner software etc are non-trivial problems for any larger CI system.
So I’m actually fine with the proposed change since it also gives me the power as a customer to say “hey, I’m paying for this, fix it.”