Myriad Pro seems to have disappeared from my Illustrator 25.2.1. I've been using it as my go-to font for years, but the only Myriad that is showing up now as available is Variable Concept Myriad. When I go to Adobe fonts, Myriad Pro shows up with the option to deactivate ... which suggests that it should be available. I just upgraded my Mac OS to Monterey and wonder if that could be the problem.