Putting tracking protection to strict essentially makes Firefox violate certain web standards. Developers aren't going to test against that, and if they are they're probably not going to be able to do much about the problems strict tracking protection causes.

If MAS fixes this, it'll be by accident and it'll probably break in the future. Firefox warns against this kind of breakage if you enable strict tracking protection in the settings. You can't have strict tracking protection + websites doing cross-domain authentication working.