I totally forgot that this threat existed!

Hope everyone got their ADRs! I assume that the vast majority of the thread has hit their 180 day mark. I keep adding and rearranging mine since more restaurants are still available--except for BoG of course...I've only been to WDW in July so going in January will be a change, hopefully for the better!
As I catch up on posts, I have a question: if I've already booked my room, reserved tickets, etc. could I still add-on the Play/Stay/Dine once it's released? I know that the LM rooms at AoA tend to miss out on free dining because it's so new--is that the case with this promotion as well? I wasn't originally considering the dining plan but I might if this offer applies to me and seems worth it.
Thanks!