> on mobile it is beyond sensible to make a warning when leaving to view external links: mobile apps and mobile browsers do do not have the capability to show the exact url you are about to open (in desktop you call hover over a link), which can lead to all sorts of bad things, first of which is spoofing your ip address.

Informing your users that they are being redirected to an external link is very different from blatantly lying to them about your competitor. The text of the warning explicitly says that mastodon is “spammy or unsafe”.

I am pretty sure if someone pastes a discord link in your xmpp client, you’ll not say that Discord is spammy or unsafe. You’ll just inform the user that they are being led to an external link.