You must be remembering incorrectly, because check-in day has ALWAYS been the catch. You cannot activate free dining before the free dining date. As others have said, you can do a split stay of room only for the days before that are not included in FD, and then a FD stay. Just make sure the tickets on your FD stay include the number of days you want with RO too. And yes, you can activate tickets before
But your way doesn't make sense to me. FD can extend beyond the end date as long as you check in on an included date. An example for this year's possible dates is those checking in on Dec 23 for a 10-night stay can have free dining for their entire vacation. Why would you want a RO after a FD stay?