All it "ever did" was send your entire prompt/context to a "free" model for harvesting. The astroturfing in this thread is absurd.
Maybe try a sensible approach first, cause so far this is assumed, for no reason, to be done maliciously. "to steal data" and the like.
Opencode's source code is public, so you can verify any claim against it directly.
During this short period - yes. Unless it finds a valid small model, or you set one yourself - it would use the one provided by zen. or you could disable it with an invalid model altogether. Good gesture for most users and something else to others.
It's *could by the way, as this was only a short window when this was a thing. It went back to not having this fallback pretty fast, i don't think it even lasted a month.