They offered a free upgrade to Poser 11 for existing Poser 10/2014 users. I'm not aware of them ever offering free upgrades to Poser 12, only 11, and I thought it only applied to owners of Poser 10/2014, because it required the online verification which would end once SM shut down their license servers.

Regardless, it's best to contact customer support for this for the most accurate information.