No, they dont care. Particularly if another provider is there. Of course you can have more than one utility serving your address that's ridiculous.
They are fighting over the same coax, you need to pay to run a new coax to one side or the other, or find where the splitter is that's feeding both locations.
Last time I saw a fios order no one cared about new sublocations, they even encouraged them because they counted as a new install instead of an upgrade.
Copper would have completed different addresses in a terminal just from a misplaced space in the address.
Eventually they would refuse service to a fictitious/not to code sublocation but only if they were running out of fibers in the terminal.