If you mean a new code base but with some similiarity to the current one (like Unreal Engine 3 to Unreal Engine 4), I mean, yes. But maybe a very different branch.
Yeah, I agree with you, that may be unlikely due to the burden to support both etc.
About the roadmap… yes, it’s been like that for a while, I agree, but it’s getting closer to completing all main features in the plans. So… what will happen after? Only improving on current features? Maybe, as there’s a lot of features already to be worked on. But it’s a little strange.