Armory access has been added to the known issues list! Keep reporting it!
I've been reporting it through the bug report form whenever I see a perk or attachment or scorestreak I can't unlock for the last few weeks, and I just checked the 'Known Issues' page and it's on there now.
I don't know when it was added, but it's after February 18th as that's the most recent archived version on archive.org and it's not on that version of the list.
The more reports a bug gets, the better chance we have that someone will actually be allowed to go and fix it. I don't think it's intentional, I just think without people reporting it, Activision isn't going to "waste" resources on it. A lot of companies operate this way.
Frankly, if the point was to make you play Warzone, why are some things completely locked out? Why didn't they disable unlock challenges in MW22 or MW23?