If you are using (the Cloud Based) Lightroom CC then all your photos there will be stored in the Cloud, if they had finished syncing.
If you are using Lightroom Classic, your folders and Catalog will match the state they were in when you did your last Time Machine back up, I would assume.
Be absolutely certain that your photos are indeed stored in the Creative Cloud. If they are, that is where they will still be even after you do the restore. If they are not and the Catalog is on your hard drive... I wouldn't count on them being there after the restore. Good luck!