The TCG is finished, as part of last fiscal year's annual plan as noted in the introduction. I would add that by "finished" I mean it's as finished as a wiki page can be; it's free to be modified and/or expanded as needed in the future to reflect practices. The draft tag remains, however, as management teams within the WMF still need to get together and come to an agreement over what this draft means in theory and in practice (i.e. to make sure that everyone is on the same page). The TCG remains a help document so the the agreement that the page is waiting for does not have to do with any notions of implementation in the sense of policy or process.
In practice, the TCG is being used in the day-to-day, project, and strategic planning work of the Technical Collaboration team. These best practices have been used for quite some time this past year, and will continue to reflect the methodology of the team's work. I am also working with the ORES team as they develop an auditing tool, helping the team align their work with the TCG as best as possible as the tool cycles through development.
And, uh...that's about it for now, I think. Thanks to all who have contributed on this and other talk pages for this project, it's much appreciated.