There's no requirement to do the training if you aren't currently instructing.

You might ring up AOPA and see what they think of this communication. The fact that it seems "local" in nature - not a national program - is troubling. You might not be required to respond, at least at this point. Get some counseling before you write back. My mailing address is in Ohio (different "district", I presume) and I haven't gotten anything like this.