I finally successfully updated Nextcloud to version 31.0.10 on my Odroid N2+ 😅
Despite all official information, an update is possible on a system running nextcloud installed via the script !
It is not necessary to buy a new hardware just to run nextcloud on your Armbian SBC in order to get the update.
I did the following:
Updated nextcloudpi to version 1.55.4 which was never released but just tagged on github Nextcloudpi tagged page on github via the ncp-config menu system (Updates/nc-update)
Updated nextcloud to version 31.0.10, again, via the menu system (Updates/nc-update-nextcloud version 31.0.10)
I don't really know why this information is not readily available on the nextcloudpi github page nor anywhere else I looked.