are these like tankettes

Sort of, although oriented specifically towards usage by airborne forces. It's basically what it says in the name - an armored weapons carrier, a way to bring along an autocannon or anti-tank missile launcher that would be too heavy to easily lug around by hand. Tankettes fell out of favor since they were just far too light to be effective among conventional ground forces, but in the specific context of airborne operations the concept still sort of works, since being air-transportable imposes some very harsh limits on the weight and size of your equipment.