In my experience with software product development, one person’s “basic core functionality” is another person’s “I’d use it if it were there”. I find that the Relay is useful without device renaming, which makes it clear to me that it is not core to the purpose of the product.
What Republic considered core functionality was clearly spelled out in the email that we received. Device renaming was not specified as functionality that would be provided during either the pre-release or initial release phases.
I agree it would be a good feature.