I'm pretty sure what he means is does a laser itself being light or heavy affect damage values.
If it's a heavy turbolaser it does more damage, but the name of the hardpoint will reflect that, it's not based on the ship. Really, as far as the heavy/light shipyard designation goes, that doesn't reflect any quality of the ship other than size (and even then there's some fudging we did for some roles). Would really be more accurate to call them small and big frigate shipyards, but that doesn't sound as cool.