I've found this issue after updating to the master after new version announcement. Just updated to to the latest master and the issue is still there.

To repeat use the following command:

bind -m insert -M insert  \ea 'commandline -b; commandline -f repaint;'
bind \ea 'commandline -b; commandline -f repaint;'

Then press Up and AltA. The printed command will lack quotes. Something wrong happened to '\ea' as well. I'm not sure concerning '\ea' but quoting was working around month before, I use this feature to edit commandline in the editor.