Not sure why people are claiming this as malicious. If Apple thought making life inconvenient for linux users was a good idea, this is about the least effective possible way to do that. And it's unclear why Apple would want to do that in the first place.

Seems far more likely that Apple was facing some sort of automated attacks on this particular subdomain (with linux UAs), and a beleaguered admin used this as a quick fix.

Or, even more probably, it's a misconfiguration.