Currently, Provisioning Manager doesn't support the LUN resize operataion. Even if Provisioning Manager does support resizing a lun, for that manually on host side, you need to rescan the lun to discover the changes and do resize the filesystem created on that lun. Same steps need to be taken care if you use system manager or ONTAP CLI. To simplify these things, you can use "SnapDrive" Host utility software provided by NetApp, which will allow you to resize your lun mapped and aswell your filesystem created on it(drive in windows case).
If you still feels that the feature is required in Provisioning Manager then you can open a RFE for the same..!
Lun resize operation doesnt break your protection relationships, the changed lun properties will get updated to secondary storage in the next protection update.
Please let us know if you still have any queries.
Warm Regards
Sivaprasad K