They (Rackspace) OWNS another Redis hosting platform: https://www.objectrocket.com/managed-redis/. It's ridiculous that they didn't migrate customers instead of closing up with a two months notice in the summer.
Weird, maybe they want to get rid of the free tier?
They could have migrated paying customers, but didn’t.
They could have migrated customers while saying EOL to the free tier. I'm more inclined to think that they had two Redis SaaS offerings and the one who was less used/less maintained lost the internal battle.