Over in the Roon forum Danny Dulai (founder) stated the following in the second post, which can be found here:
We expected to fight hard for the existing lifetimers, but Harman was awesome and didn’t even consider not continuing to support them!
Things can always change with acquisitions - time will tell I guess. I could see lifetime subscriptions to purchase (new) coming to an end at the very least. I could also see devices needing their own one-time purchases of Roon activation for devices - like DIRAC - for both lifetimers and monthly users/payers.
Regardless, and like many others here, hoping the current lifetime subscriptions continue to be honored.