Most likely not being enabled in the software for entertainment purposes, these aren’t a surveillance tool if the airlines wanted to have security cameras they would’ve installed them already and not in a place that is easily accessible by the passengers so they could cover them.
This is utterly useless for anything but to make video calls or for kids to play stupid games with.
Many infotainment systems already have had microphones in them even on older planes with international flights you had the ability to make calls even in coach.