At this point, I don't think TSP on this particular corridor is in MBTA's court anymore, which is probably why it's vague. TSP requires either equipment at the traffic signal box or GPS-based awareness of BTD's central traffic control to know when to turn the signal. The Green Line Transformation team is likely negotiating that need system-wide with BTD, but again, the implementation will be dependent on what's there today and what BTD can do at the intersections along the line.
I can't believe it's taken this long for the consolidation work to actually happen...I remember going to public meetings for this as late as 2016 and definitely as early as the Dr. Bev Scott years. I seem to remember that this was contingent on Comm Ave Phase 2A work (Amory to Alcorn Sts) wrapping up now and Phase 2B work (reconstruction of Comm Ave over I-90) that wrapped up in 2018. Future phases beyond Packards Corner fall into
Comm Ave Phases 3 & 4 which is somehow still in design phase after 6 years and will likely benefit from the GLT team's capital project experience... And they'll need it with the grade changes on some of the stations...
Right off the bat, some of these could be addressed with changes to the road geometry (road diets to reduce overall lane count and width to encourage slower, safer speeds), which gives you more room to build ADA-compliant stations. Moving eastbound Warren Street to a far-side stop immediately solves the grade issue and helps with TSP and begs the question about consolidation with Allston St. Likewise, moving Sutherland Road further west instead of between Sutherland and Colborne gets the platform onto more level ground.