>The MBTA expects to collect 450M in fares this year, making up about 25% of the budget, this project will last about 20 years given the last fare implementation, so with straight line depreciation that’s still only 10% of expected post pandemic revenue

From their post.

But even if they didn't include that, they didn't say "let's throw good money after bad money". They said "cancelling the money wouldn't get the money back" with an unspoken "so your comparrison only makes sense in hindsight"