Back in the 1990's Adobe had a fairly decent selection of Type 1 Multiple Master fonts. A couple of those (Nueva MM and/or Tekton MM) were bundled in apps like Adobe Type Manager, IIRC. It would be great to see more of those MM typefaces from the past revived as Variable Fonts.

Some of the more familiar Adobe Originals have been remastered as Variable Fonts. Those include faces like Myriad and Kepler. An equivalent to Minion MM is included as a system font in certain Adobe apps, but isn't available via Adobe Fonts.

There are various other Adobe Originals MM typefaces that seem "lost." Some aren't available in either regular "static" form or variable. Penumbra was a beautiful all-caps typeface that had variable weight and serif axes.

I'm guessing Adobe wouldn't legally be able to remaster every type family they distributed in T1 MM format in the 1990's. ITC Avant Garde or ITC Garamond might be a problem with Monotype now owning ITC.

The old T1 MM fonts had limited character sets; I'm not really asking for Adobe to fully flesh-out those old MM fonts with expanded OpenType-centric features (although it would be nice). The Minion Variable Concept fonts have limited character sets compared to the glyphs in Minion Pro. But it would be a lot better than nothing for Adobe Fonts users to have access to those old MM fonts in OTF Variable format, even if we had to settle for fonts with no more than 256 glyphs.