This should be covered by snapshots already. When you remove a snap with snap remove foo it automatically creates a snapshot of snap data found under /var/snap and under users’ homes. (not to be confused with snap remove --purge which does not save a snapshot).
maciek@galeon:~ snap saved
Set Snap Age Version Rev Size Notes
312 test-snapd-zfsutils 13.8d 2.2.2 x1 253B auto
maciek@galeon:~ snap remove wormhole
wormhole removed
maciek@galeon:~ snap saved
Set Snap Age Version Rev Size Notes
312 test-snapd-zfsutils 13.8d 2.2.2 x1 253B auto
313 wormhole 2.32s 0.16.0+2.g1bd72f3 509 324B auto
where the content of the snapshot for wormhole is:
galeon# unzip -l 313_wormhole_0.16.0+2.g1bd72f3_509.zip
Archive: 313_wormhole_0.16.0+2.g1bd72f3_509.zip
Length Date Time Name
--------- ---------- ----- ----
125 1980-00-00 00:00 archive.tgz
199 1980-00-00 00:00 user/maciek.tgz
467 1980-00-00 00:00 meta.json
97 1980-00-00 00:00 meta.sha3_384
--------- -------
888 4 files
Perhaps it’d be useful to show a short info that the data has been archived and can be restored or they can then use Snapshots | Snapcraft documentation to export and inspect it. I’ve filed Bug #2114704 “indicate that snapshot was created during snap rem...” : Bugs : snapd