If you walked through the IR steps where you performed the restore and then migrated to production within Veeam, at the conclusion of the migration, it should remove the NFS mount. If you cancelled the IR and didn’t migrate the VM, it should remove the NFS mount. If you performed the IR but migrated the VM outside of Veeam, there may be a restore job still running that you can cancel. If it’s not there, I’d remove the NFS mount from your host. Also, if you cancel the job and for some reason it’s still not removed, I’d remove manually.
While there’s not a huge issue with leaving it there, it’s unnecessary clutter and if the host(s) are still looking for that mount, for instance during a reboot, it could cause unnecessary delay. The same thing happens when VMFS datastores are removed incorrectly from a host as the host still will have records of that volume being there and will try to connect to it. For sure, if you’re no longer using it, I’d clean it up.