That solves ownership in terms of making sure the memory isn't deleted while something is owning it but, at least from my quick read, doesn't solve ownership issues related to concurrent access that Rust's ownership model does solve. Is that reading correct?
You are right. But it's not needed in Lobster, because threading model is different. It doesn't have concurrent access problems:
> Lobster built-in multi-threading functionality ... is different from multi-threading in most other languages, in that it does not allow threads to share memory or any other VM state.
http://aardappel.github.io/lobster/memory_management.html