How should Apple or Google Play decide when to cut off an encrypted messaging app when faced with evidence of abuse?

Today Google Play banned the open source Matrix client Element due to abusive behavior that the messaging service had already dealt with https://arstechnica.com/gadgets/2021/01/google-play-bans-open-source-matrix-client-element-citing-abusive-content/

Google has since restored Element. But it's a tricky decision, since Element is a client to a decentralized messaging service; banning it is akin to banning Google Chrome after learning about something nasty on the World Wide Web.

Banning the open source Element client from Google Play may also have briefly cut off the French government & the German armed forces from being able to install apps to participate in official chat communications

CAT Lab uses Element; it's the only widely-available encrypted chat with content moderation. It's concerning that other encrypted chat services aren't working harder on this

If society doesn't figure out encryption+moderation soon, we're in for trouble https://www.theverge.com/22249391/signal-app-abuse-messaging-employees-violence-misinformation

Great thread on this with @d_obrien, who is such a thoughtful conversation partner! https://twitter.com/d_obrien/status/1355723626545356800