It’s indeed related to the recent security fix (your user can’t read anymore the file /etc/yunohost/installed if not root)
I think a quickfix may be to run: rm /etc/profile.d/check_yunohost_is_installed.sh
(this file is only used to resize the rootfs + display the message you saw, so it’s not useful anymore once the system it set up, hence it’s safe to delete)