FYI: Signal stores all of your messages on your device. If something happens to them there, they’re gone. I’m not saying that justifies an update nuking your messages. Just explaining for anyone who may not understand that. There’s no central database storing your data long term. Which is a feature.
Try FairEmail. It’s the closest thing I’ve found.
Ironically, many americans are now using chinese platforms to freely discuss things without fear of the US government.