I've just filed a bug report on emacs and was advised to report it here too.
It's bug#27140. Basically, when I start GUI emacs (macOS, but also Aquamacs, also reported in Xubuntu and GTK+/Linux), I don't get the default org-mode bindings. Only emacs -nw gets them. Even if I start both with -Q, I get the exact same behavior: proper default key bindings for org-mode in emacs -nw, some bindings overridden in GUI emacs. The discussion thread on help-gnu-emacs is here: http://lists.gnu.org/archive/html/help-gnu-emacs/2017-05/msg00306.html Let me know if you need extra information. Jean-Christophe