There is another use case for disappearing messages: protection against domestic violence. If the violent partner checks the victim’s device, seeing messages might incite an attack.

I don’t get it. If one’s phone is on the same LAN as the PC, why not just start sshd on the PC (if not already running) and send the files using scp?

AFAIK there was another problem with the list of installed fonts (only relevant if the mentioned experimental feature is not used): the list was retrieved from the OS in randomized order and then kept forever. This allowed distinguishing even amongst users who had only the default fonts as shipped by the OS. Will they be either sorted alphabetically now or at least freshly randomized every time?

This looks like they want to stop people from using encrypting clients, so they can continue to read your mail and create targeted ads.