Do you have a permit from the city to rent your place out? If you do, then you are already in the system, so to speak, and will receive appropriate inspections at whatever interval they are running them now. The program is an alternative to the city inspector coming out to inspect your place. You are not required to participate...it is purely voluntary.
If you don't have the proper permits to rent the place out, then it's entirely possible that your insurance company will give you problems (not to mention the city.) However, that is not related at all to the voluntary program you are asking about.