The current info suggests that soft landings will be given, but personally if I was that close to Plat qualification I'd find some way of working the 3 nights in, just to be on the safe side. You still have the whole of Q4 and rates are relatively cheap in this period. BTW, have you booked a meeting room to get 10 nights yet?

Rollovers are not a thing, sadly (Hilton wins on this score).