You wouldn't even need "piracy" in this case, just buy one copy of the game and figure out how it phones home, and then pick your favorite method of tricking it into reporting ludicrous amounts of installs, which would significantly outnumber pirate copies.
No it doesn't, fraudulent install tracking by Unity could hurt the developers. If pirated copies count as valid installations, that means that the system is completely unauthenticated and will be abused.