Note that `MANAGE_EXTERNAL_STORAGE` permission doesn't allow access to /Android anymore either (it's blocked by OS permisisons) so it won't help Nextcloud to retain it either.

Thing is, Nextcloud doesn't need that permission since they can do what they do now with SAF which is how Google determines eligibility for the exception. That is - if you can do it with SAF, you don't need complete access to all private data via MANAGE permission.