It was unintended. But it was part of the bigger picture, and I think it is correct and sensible behaviour. I expaneded the Resource interface with (among others) the Name method. This is the method used in the prefix methods.
And you can set that value in the “resource metadata”. And it kind of makes sense for bigger bundles to include the folder.
I think I’m going to just update the release notes about this. I think. But that will have to wait for later …