Hi, working for a company that has 2.x and am working on 3.x.
Can't say too much but it's a big shift. The rewrites are significant; under the hood I know less about.
It's certainly a big focus for RH. I think it's great that they've embraced Kubernetes and Docker, but I can imagine it's going to frustrate early adopters who have already got used to one set of terminologies.