With the closure of the bug for Hackasaurus, we have now finished the 19-month MPL 2 upgrade project :-) All Mozilla software which used to use the tri-licence now uses the MPL 2.
Particular thanks go to Francesco “flod” Lodolo, who was the driving force behind the last big push to get the outstanding l10n repos relicensed.
(A post like this one is, of course, begging for someone to point out some files I may have missed. There are still a few tri-licensed files in the tree because they come from upstream projects that still use that licence. If you still think I’ve missed something, please file a licensing bug.)