I think that the only relevant stuff in the link is the id, it seems that the category name is actually ignored.
For example, instead of:
you can just write:
and will end up in the same page.
So it seems that only the id matters (which makes sense, if you want that links to categories remain working even after a category rename). So I don’t know if this will ever change (and I don’t know how much impact ids will have in SEO, but maybe they are not really a problem).