No. Deactivating a driver only stops them from showing up in your Drivers list, driver groups, and most reports going forward.
Every activity, file, and report already on record for that driver stays exactly as it was and remains fully accessible at any time — many reports even let you choose to include deactivated drivers directly.
Reactivating the driver later — simply by uploading a new tachograph file for them — doesn't need to "restore" anything, since nothing was ever removed in the first place.