I am also receiving an HTTP 403 (which means Forbidden, btw. Blocked.) error in my RSS reader. I use Tiny Tiny RSS. It's been unable to pull the MacRumors feed since last Thursday, while all my other feeds continue to work normally.
And likewise, I've been using this setup for many years now and haven't made any changes on my side. TT-RSS itself hasn't had an update in a couple months, so this block is unlikely to have been anything changing on my side.