Ungroup remembers layers (like InDesign)
Jabulani HARVEY commented
Yes please to "Ungroup remembers Layers" in Illustrator and I would also suggest that Indesign inherit the "Save selection" feature from Illustrator, while we're at it.
literally can't believe this still isn't a thing
Oliver Malms commented
long, long time ago, Freehand had a great function (indeed it hat a lot of great functions that I am still missing in Illustrator): When you grouped Objects from different Layers, it remembered the original layers of these objects. So you could group them, do with them whatever you wanted and after ungrouping all objects went back to their original layers what was a very useful function. I whish, Illustrator wound offer something like this, too...