I agree if this is meant to prevent hoarding of seats (that end up going unused), there is a better way to accomplish this (like given plats a certain number of changes/year).
It smells like an attempt to get more $$$ from people already buying their J and Y fares....
I, like most of us, spend more money on NW (they are rarely the cheapest option ex MSP) as I have valued the benfits of being a Plat Elite....
Now it does seem the program getting watered down and we getting the worst of both airlines.... causing me to really rethink my loyalty.