don't quote half a quote to make a point. here's the rest

"...are scanned for spam and viruses to pursue the legitimate interest of protecting the integrity of our Services and users. Such inbound messages are scanned for spam in MEMORY (i.e. it is not persistent), and then encrypted and written to disk. We do not possess the technical ability to scan the content of the messages after they have been encrypted."

mullvad has gone ram only for similar purposes as data stored in ram is temporary and not persistent.

using pgp or encrypted messages for private conversations is essential. if you don't anyone can read the contents of said messages. this is not a revelation, it's common sense and a problem proton solves as transparently as possible.