Yes it did. I figured it out on accident After shooting a few grenades off then forgetting about them and trying to do something else.

I imagine there will be a lot more weapons to choose from in the main game (3 different kinds of bolters didn't excite me much, either). I've seen both melta weapons and plasma pistols in screenshots, and the former in particular could be very interesting depending how they implement it.

There are certainly enough other weapons you can give the little guys in the tabletop game they could get inspiration from, and I suspect they'll make up some (never heard of a stalker boltgun). Flamethrowers, plasma cannons, missile launchers and so forth. Even more if you pick up terminator armor at some point in the game.