Once every 3 months is too frequent. Imagine curl broke compatibility every 3 months and you had to relearn curl. How terrible! I'm pretty sure you'd use something else after a while.
I'm not saying React should be as stable as curl, but it should be striving to become that. The JavaScript community loves to have these eternally evolving libraries that are never actually stable and that's not good for anyone. You should have a long term plan that says "we still don't know what this library should be, but within 2 years we should have it figured out". In reality it feels like JS libs only become stable after they've been abandoned.