Do I have to restore from the back up?

smtre wrote:

I backed it up before the repair, as a precaution.

Do I HAVE to restore from the back up or am I good to go now that it is up and running ?

If everything is still there (ie your data) there is no need to restore.

The current backup is a prudent approach if you value your user data.

Backup early and often is the rule of thumb.

If Apple fixed the issue and your data is still complete, you don't have to restore from the backup.

In case you used TimeMachine to back up your data, you can always restore missing data of files, without erasing the whole MacBook Pro.

Restore items backed up with Time Machine on Mac - Apple Support