Thanks for bringing this up - an update is long overdue. We know that managed DBs are the elephant in the room.
The truth is that we’ve been heads down work on our own managed MySQL and Postgres managed database services 
More to come on this topic.
We still want to offer Supabase. We’re waiting for them to support highly-available (HA) database. On AWS, where Supabase’s original product deploys, this isn’t as much of a problem. On Fly, HA (2+ nodes) is essential for a production-grade database.