I understand "partly" if the pre-owned market price decelerates, mainly due to owners liquidating for cash to pay immediate expenses or invest, although such owners are usually cash heavy and don't usually need to liquidate too much.
But ADs dropping prices sounds strange to me, because yes demand has dropped, but so did supply - with all Swiss manufacturers closing shop. I'm curious to see how this market will behave, nevertheless, I have little faith that prices will go anywhere but the customary +5% per annum