If what you really want is free dining, book a package. Add dining, or don't add dining. If you're going to get the dining plan whether it's free or not, add it when you book. You dont have to pay for the package in full until 45 days from arrival. If you won't get it if it is not free don't add it.
If a free dining offer is made that includes your dates, then call Disney (you can't do this online, you have to call) and ask them to apply the free dining offer to your package.
If you won't go at all unless there is free dining, you might as well wait to book until you see if an offer is released for your dates.
If you already have a reservation booked, the above post looks like it's correct about the current status of room reservations regarding the dining plan.