The list includes the web properties served by Wikimedia Foundation as of last Sunday.
Also, it looks like mastodon.social is nearly in the top 10k, certainly if you combine Fediverse traffic. That feels new and significant. I wonder if there's been at attempt to estimate its share and position (eg as if it were centralized).
This Mastodon instance is for people interested in technology. Discussions aren't limited to technology, because tech folks shouldn't be limited to technology either!