It does make for an interesting example. Without knowing copy-write laws I would argue that you still own the content on the other platform they are posted under you account which you have access to and will gain any rewards on them.

It is also still STEEM just a breakaway from the main chain into a new direction but everything existing on hive already is actually STEEM until now with rewards payed out on it. The same a viewing your content on busy.org or any of the other STEEM interfaces where STEEM blockchain can be accessed. Everything posted now is HIVE and your content won't be showing up on the chain going forward.

I can also see where you are coming from but don't know how strong an argument that is. It would be interesting to find out how it works as i'm not sure myself.