It sounds like locking down the API was an entirely deliberate decision made at the same time as removing platform data from the website, which means Chesterton's fence[0] applies - we should work out why that decision was made before criticising it.
Discussion upthread is about commuters being pushed onto the tracks, which sounds like a good reason not to display data that isn't 100% certain.
I've never heard of "Chesterton's Fence" before and appreciate the introduction to the term. That said, I don't think your application is correct. The OP in this case is not the agent of change — he did not "reform" anything and does not have the capacity to act, he just analyzed/synthesized existing data.
(Also, on reflection, "Chesterton's Fence" is an unnecessarily complicated and overly verbose way of saying: "The MTA probably has a reason for the change.")