All in this world is possible, maybe not now, but tomorrow.
In the past, several applications was develop without take into to acount the posibility of export his menubar, like for example the Gtk2 applications. This means, that will not be possible export the menubar as they are. Then the only solution was create a patch to this type of applications, to be possible export it, a thing that was implemented by canonical to be used in Unity. The name of that package that contain the patch is unity-gtk-module:
The Gnome developers are against to use this type of patch, and they have a different conception of the desktop, so a solution that come from Gnome apparently will never going to happen. See in the last paragraph:
On the other hand, canonical developers dropped the Unity desktop in favor to have a more pure gnome desktop. This also means probably, they will not want to continue providing support to his patches for new ubuntu releases. If this occurs some one else will need to do that or will not be possible.
So, to answser the question of if it possible: Yes, is possible replicate all that unity provide inside gnome shell. Also is possible use all that canonical was created from the unity desktop. As example:
All in this world is possible, maybe not now, but tomorrow.
In the past, several applications was develop without take into to acount the posibility of export his menubar, like for example the Gtk2 applications. This means, that will not be possible export the menubar as they are. Then the only solution was create a patch to this type of applications, to be possible export it, a thing that was implemented by canonical to be used in Unity. The name of that package that contain the patch is unity-gtk-module:
https://launchpad.net/ubuntu/+source/unity-gtk-module
The Gnome developers are against to use this type of patch, and they have a different conception of the desktop, so a solution that come from Gnome apparently will never going to happen. See in the last paragraph:
https://wiki.gnome.org/Design/Playground/HUD
On the other hand, canonical developers dropped the Unity desktop in favor to have a more pure gnome desktop. This also means probably, they will not want to continue providing support to his patches for new ubuntu releases. If this occurs some one else will need to do that or will not be possible.
So, to answser the question of if it possible: Yes, is possible replicate all that unity provide inside gnome shell. Also is possible use all that canonical was created from the unity desktop. As example:
https://gitlab.com/lestcape/Gnome-Global-AppMenu