Sorry, but that makes no sense at all.
Sure, the distinction makes sense, of not wanting to give someone access to future updates, but conflating versioning with downloading is insane. What if someone did download something, but then gets a new computer and is unable to access stuff they had added to their library in the past?
It's not particularly difficult to implement this correctly; just put a tag on the library item's data saying that it's locked to a specific version, and they can't download any newer version than that. Saying they can't download it at all is completely wrong on just about every level.