For the record, the Republic flights on E175/E170s are already operated this way (for all codeshares UA/AA/DL). At top of decent the FAs start preparing the cabin. Then when descending though 18,000 feet the pilot monitoring will say "Flight attendants please prepare the cabin for arrival". Below 10,000' the FAs should be in their jumpseats and be ready for landing. If there is a chance for turbulence then we will have the FAs remain seated longer after departure or we may have them start the clean-up process earlier than usual.