Yes. It'll work on all team weapons for all factions. Except for the 5-man part, you'll get 4-man weapon crews as OKW. And yes they'll be using the default rifles of their squads rather than shitty team weapon crew member guns.
For maximum abuse, equip 3x Jaeger Infantry vision bulletins as OKW and recrew stuff with them. Sniper vision on your team weapon squads, because that's balance.
If I recrew a pak gun with Jaeger Infantry and take casualties, will the reinforcements be Jaeger or normal crewmen? And which MP cost will be used to reinforce?