They are sending them out according to original purchase date, I got mine a few weeks ago. Since you are the second owner, I'd be willing to guess that SoA doesn't have your contact info. You can call (or go by) your dealer and give them the VIN number and they will tell you if your car is eligible.

To ensure you always get any recalls or service bulletins:
a. Look in the owners manual, find and send in the "Change of Ownership" card to SoA.
b. Go to http://www.my.subaru.com and register your information there.