6 points
To be fair, mastodon.social is Mastodon instance, and all Mastodon instances (that support signup at all) will show a Sign Up link for themselves. This is true from the biggest instances to the smallest ones.
But to bolster your point, the Mastodon app could push exclusively for signups on the newly acquired mastodon.social domain, and hide other options behind a dark pattern… Like how Element does this when you try to log in to a Matrix server.
5 points
Yeah sorry, meant https://joinmastodon.org instead of .social
