LibreWolf won’t be impacted, they’re already considering to move to Phoenix instead.

Phoenix: https://codeberg.org/celenity/Phoenix

LibreWolf issue: https://codeberg.org/librewolf/issues/issues/2823

Phoenix is also used by IronFox.

Phoenix is also an alternative which can be used with Vanilla Firefox.

Since the author edited the title, Phoenix, according to the credits does not rely on Arkenfox at all.