The biggest threat to Twitter under Musk is a multi-platform app that serves Twitter, Mastodon and other services.
Such an app would act as a catalyst for moving to other platforms by lowering the switching cost
I have a scheme for a multi-platform app that Space Elmo can't block. Click on the Twitter feed and it takes you to the Web interface if the API is down.
The client ID will be set to whatever works since my client is built around WebView which is a wrapper around Chrome.
Happy to share this idea with other client developers. My goal is to get people to use end-to-end secure communications, not to have to write the entire client myself.