From my understanding a lot of the working going into shell & mutter atm is removing the x11 bits and clean-up old code since that's holding it back. Seems a bit weird to write an entire new compositor especially if the plan is to make PureOS the same on the desktop & mobile. Maintaining two compositors seems illogical.

At least it's just talks now, I would like to see some more technical perspectives from both GNOME and Purism before they make a choice.