It's too easy for data to get deleted by mistake. There should be warnings in more places.
For example:
1. when creating a document, while logged in

When this box is unchecked, the document has no owners so it is deleted automatically after 90 days of inactivity according to https://docs.cryptpad.org/en/user_guide/share_and_access.html
I'd suggest unchecking the box should show a warning underneath the checkbox such as "This document will be deleted after 90 days of inactivity because it has no owners." and possibly also showing it as a modal/pop-up with an option to not show it again.
2. when creating a document (not logged in)
The above screen is only shown when signed in, so this case is different. Not-logged-in users do see this in the drive home page already:

But I think it should be shown here as well, when creating a doc, for emphasis, and for consistency with logged in experience:

3. while viewing a document:

Somewhere in the header there it should say "Document will be deleted automatically in <x> more days of inactivity"
This would make sure all editors know that the document will be deleted, not just the creator, who may not care as much and may neglect to relay the message.