Compare to the last time I did this, there does seem to be substantially less waiting list movement. That year, the WHS waiting list moved a lot, PHS didn’t really, I didn’t hear of any SPGS offers from the waiting list, but there was a scattering of other ones moving (Sutton and KGS, from memory). But I’m at a primary so this is all about people who posted on MN, it’s not something that’s talked about at school. I’m sure someone with a dd at a prep would have a better overview.
The deadline for responding on state places is 14 March, so I think there might be some movement after that, as people who have paid a deposit to have time to think about an unexpected Tiffin offer potentially take up that offer and free up a place.