I’m on 2 of their FB forums - Science and general Users. Their user base is non-athletes: those into general health and/or fitness, but not athletes. Even with their projected 2022 features, I don’t see them having much, if any, impact on HRV4training business.
As for Gen 2 users, for those that upgrade to the 3, the subscription service is free for the lifetime you own the 3. And given the improved and new sensors and algorithms, I would expect that reliability may improve as well.
I posted a thread in the FB Oura Science group a few days ago about user experience of integration of the Oura with HRV4training. Some good responses. You may want to take a look.