To me it's great that Twitter is doing something similar to 4chan, which is making publication temporary. Musk probably realized that most posts on Twitter is worthless garbage anyways (which is also true for almost all opinion/emotion based conversations on the Internet as well, this ones too) and incapable of constructing any meaningful solution to the world's problem. Why paying all the money to store these volatile, useless and maybe even destructive information?
Also, this policy has great effect of... shall I put it... testing the real social value of Twitter. Musk brought it for like $10B? That's way over priced ;)