Depends on what type of reservation you have.
If you are a DVC member booking through member services, no. It's an entirely different reservation system and they don't even have to book packages to get
DDP.
If you are an annual passholder, no, you can get a ticketless package.
If you are eligible for the military room discount, no, you can get a ticketless package.
If you don't fit any of these categories, then yes, you have to buy a room package with at least 1 day park tickets in order to get the dining plan.
All this goes out the window if you are talking about
free dining - no matter who you are, you have to purchase at least 2 day park tickets with a package to get free dining.