> Anecdotally, many of them are aging out

Ageing and out and neither being replaced directly or reduce numbers coming in at the bottom/mid as others move up, is still a drop in people. If part of the reason there is less need to bring people in lower down is that a few are being expected to do the work of a few more due to automation via AI, then that is AI replacing them, just not quite as directly as “we need less people as AI makes each more efficient so there are redundancies”.