MBTA board meeting today will include an update -- not a vote -- on service cut proposal. Here's some recent news about all that...
The proposal was unveiled last month after a few months of hints and warnings that big cuts were likely: https://www.bostonglobe.com/2020/11/09/metro/cash-strapped-mbta-details-planned-service-cuts-take-effect-next-year/
The spark notes version: commuter rail closes at 9, 25 eliminated bus routes, subway frequencies
, most (but not all) buses as well. Green Line E branch ends at Brigham Circle. Weekend commuter rail and all ferry closed outright. https://www.bostonglobe.com/2020/11/10/metro/quick-guide-potential-t-cuts/

This isn't just a MBTA problem. It's afflicting basically every US transit system that depends heavily on fare revenue. That refers largely to a handful of systems that have a high number of white-collar workers who have mostly stayed home since March. https://www.bostonglobe.com/2020/12/03/metro/mbta-not-alone-planning-steep-service-cuts/
But the MBTA has taken a unique position compared to other big transit agencies: any new federal funding may be used for future service, not to keep current service running with ridership so low. https://www.bostonglobe.com/2020/11/13/metro/mbta-service-cuts-appear-inevitable-regardless-federal-bailout/?p1=StaffPage
There's been a lot of local pushback from political and municipal leaders, including Mayor Walsh, who is scheduled to hold a press conference further voicing opposition shortly: https://www.bostonglobe.com/2020/11/16/metro/across-region-officials-passengers-seek-put-brakes-mbta-service-cuts/
Why is the MBTA planning this? Well, the short answer is they've lost a lot of riders and thus fare money that has been covered so far by CARES but may not be in the future...
... And as we await a vaccine, it is worth noting that even looking out beyond the pandemic a lot of white-collar professionals expect to take transit less: https://www.bostonglobe.com/2020/11/26/metro/lot-boston-commuters-expect-start-driving-after-pandemic-survey-says/
Meanwhile, as the virus surges right now, there are signs ridership isn't even living up to the T's current conservative projections. (Based on October data.) https://www.bostonglobe.com/2020/11/28/metro/virus-surges-traffic-mbta-ridership-are-stalling-again/
But there is a chicken-egg problem here: How will the MBTA know there is rider demand to bring back eliminated services if that service isn't there for riders to show demand? https://www.bostonglobe.com/2020/12/05/metro/if-mbta-cuts-service-how-will-it-know-when-bring-it-back/
And as @bytimlogan explored, this could flummox housing developers and planners, who have put a lot of energy into what until recently appeared to be a regional imperative to put homes near transit: https://www.bostonglobe.com/2020/11/26/business/mbta-cuts-imperil-transit-oriented-building-boom/
Anyway, one of the more notable developments came last week, when the MBTA's outside budget review board said it doesn't buy the agency's projections and sees no justification for at least the most severe cuts on the table: https://www.bostonglobe.com/2020/12/03/metro/mbta-overstating-budget-problems-ahead-service-cuts-report-says/