But Ubuntu is not Dalton Maag's sole client. If you follow the foundry's blog, for most of this year they've been doing a major project for Nokia and one for the 2016 Olympics.
Since the monospace was released and the initial script set was done, adding a new language or a new face/weight is likely to be something that they'd only tackle on a periodic basis between other projects. I have no idea if there are additional scripts that the company has agreed to take on, or if that's something that they revisit with Canonical. The issue tracker on Launchpad was largely the purview of Paul Sladen, and I believe he's off doing other things. Neither of things equates to the font "pushing up daisies"; I would hardly think things like continually adding extra weights just to be doing something would be worth the time.
So you may not see a whole new face added again until someone comes up with a different use case (like one cut for extra-small point sizes, if Canonical decides the existing one doesn't jive with mobile devices or whatever). But who knows; DM could surprise us with a full "Extended" face next week.