Movable Structures

i'm pretty sure 'postponed' just means they ran into some sort of difficulty and decided to work on things they knew they could get done faster instead, just for the moment, so they can get unity up to speed with java asap.

I think that in this case "postponed" just means "delayed do to lower priority". Technically there is a basis for moving structures, it is very similar to how blueprints are rendering before placement, but unlike blueprints together with rendering they should include collider. But this basis is not enough - there should be in-game tools to create these objects, survival-friendly mechanics, craft stations, GUI and so on, and all these things should be done from scratch as we didn't have similar mechanics in Java. So, things that already exists in Java have larger priority then completely new due to version switching

"Postponed" indeed just means we're currently not working on it and we have no ETA for it yet - but it's still planned (otherwise we would remove it from the roadmap)

For Moveable Structures, we'll probably start working on them once the most important features are implemented (and the new version has finally replaced the Java version)