I liked the new behaviour personally
Even to make extra sure (though I already was), I have tested it on a GIMP 2.8 and on GIMP master just now. That works.
https://www.youtube.com/watch?v=SekYlC4ON_U
I tried with 2.8.14 and 2.8.18, both running on Mac OSX. As you can see the Command-E option only shows up after I do "Export as".
https://bugzilla.gnome.org/show_bug.cgi?id=769359
The whole idea around this and the way they decided it to work is a mess.