According to FB posts from existing Oura 2 users who upgrade, it’s free for lifetime (that you own a 3).
I can confirm this. I got the upgrade notice in my Oura app. I’ve been using a gen 2 for two and half years. I got $50 off and a lifetime subscription for free. I’ve seen some other users say they purchased their gen 2 ring within the last quarter and got $100 off. A blog post on Oura’s site mentioned that return of the gen 2 ring was required for the lifetime subscription but nothing in my checkout process mentioned it.
