I never had any problems accessing any Apple website via tor at all. That includes Software Updates, discussions, developer member area and forums, iTunes Connect, etc. Everything works just fine over Tor.
It seems that discussions.apple.com blocking Tor is new.
From 20+ years of experience in arguing with Apple I know that without filing a RDAR nobody listens. If you have access to the Apple Bugreporter: rdar://18008506
Best regards MacLemon