This is a true and interesting factoid, but I don’t see how it ties back to any transit issues. Unless you think buses having access to the northern and southern state would meaningfully improve regional transit?
Funnily enough a factoid is something that is false but sounds plausibly fact-like.
At the time most of his projects were built, African Americans were only about 5% of NYC population rather than the 20-30% peak thru today. So it’s kind of backwards looking to assume they were top of mind in his decision making either way.
There are commuter express buses, but often they are restricted to the Interstate (there is one for the entirety of Long Island’s millions of people) or the arterial roads with traffic lights
And why shouldn’t private buses be able to use the parkways either? Plenty benefit the public, like the Chinatown buses.