Alt+F, X used to close the file you were working on. Now it closees the whole application, without any warning. Alt+F, C now closes an individual file. It's taking me a surprisingly (to me! It shouldn't be to the user interaction specialists a company the size of Autodesk should be having design their GUIs) long time to adjust my muscle memory.
An extremely minor thing of course, but adding new customer frictions for absolutely no reason is just so dumb I have to be annoyed anyway.