It's been in what I would call "project management hell" for years now. Check out the Planning Timeline section on TransLink's page about it here.
I think next steps are to create a business case in order to figure out cost of construction and how to secure funding for it. Years ago I remember UBC was weirdly against helping fund this extension that would directly serve the campus, but they may have changed their attitude in years since. ๐คทโโ๏ธ