iirc, no.
but i like the mechanics of recrewing a weapon with certain squads, to make them better.. like KCH 88s that survive 7 sniper shots, or KCH MGs, that kill flanking squads without repositioning... i always found that funny :-)
That's ok, but getting a better crew with cheapest possible option doesn't make sense. I don't like the idea that it would be better to immediately kill the original crew and then replace it with combatwise identical crew, but with a considerably lower population cost. Especially now that the upkeep is dependent on the used population and not entities.