Just noticed that there's another higher-ranking thread here:

https://news.ycombinator.com/item?id=35421034

Comments moved thither. Thanks!

It’s interesting that the Tor Project Team itself is involved in this also. From the title and comments in the other thread all I gathered was that Mullvad had made a fork of Firefox with similar privacy settings to some of those found in Tor Browser. But I didn’t know the Tor Project Team was directly involved with the Mullvad Browser!

Mullvad is something like 'Platinum' Sponsor of the Tor Project. It might possibly be the reason Tor guys helped Mullvad.

https://mullvad.net/en/blog/2020/5/27/mullvad-vpn-sponsors-t...

https://www.torproject.org/about/sponsors/

https://www.torproject.org/about/membership/