This is Reddit blocking Feddit.uk from requesting the page title, though. "maam", a user of feddit.uk, wrote the link there, and feddit.uk then opened the page behind the link, in order to get the title of the page. The title provided by old.reddit.com was "Blocked", and that's what feddit.uk wrote there.

So, neither feddit.uk nor lemmy.dbzer0.com are blocking Reddit. To some extent a block seems to exist in the opposite direction already, though!