At X-COM laser weapon has NO ammo at all.
One of the things I liked about this was laser pistols. You always had a sidearm for those boards that just seemed to drag out forever (base raids, anyone?) that at the least could ping the enemy to death over enough time. These were especially useful with the rocket crew. They were my wall clearers and NO team, even end game, went out without two freshly recruited rocket boys for removing irritating terrain... however, they eventually ran out of rockets.
I don't actually see us being able to generate a map of that size in this remake with the current engine, but who knows, maybe I'll end up happily surprised.
As to lasers in general, I've pretty much stopped bothering with them. They don't carry enough shots and don't pack enough punch (even heavy) to be worth their weight. I'd rather run around with SMGs or plasma pistols with 3 or 4 reloads. If they went ammo-less it might balance off the significant weakening they got in a past release.