The Ubuntu GNOME team will be working with Canonical on the desktop to be found by default in Ubuntu, thus making a separate Ubuntu GNOME spin unnecessary. Jeremy Bicha and Tim Lunn of the Ubuntu GNOME community confirmed their plans in today's Ubuntu GNOME 17.04 announcement.
As a result of this decision there will no longer be a separate GNOME flavor of Ubuntu. The development teams from both Ubuntu GNOME and Ubuntu Desktop will be merging resources and focusing on a single combined release, that provides the best of both GNOME and Ubuntu. We are currently liaising with the Canonical teams on how this will work out and more details will be announced in due course as we work out the specifics.