I suspect these were seldom used, but they were occasionally used by people to communicate sensitive information to members of our team. We will publish guidance on securely contacting us via alternative methods later this week.
You now have the option to permanently decrypt your DMs with a new button in each message, as well as an option to bulk decrypt all of your messages in your profile.
If you decrypt your DMs, they will be stored in plaintext in our database like any other forum information (although I will note our database and all of our systems use full-disk encryption on the hardware level).
If you do not decrypt your DMs by the end of February, they will be permanently lost when we disable and remove the plugin.
I suppose one could update their PG profile with their Matrix identity, and securely chat individually, with e2ee enabled (given PG already has an established space on Matrix).