So can the Federal Government exert pressure through "financial resources" or "indirect political pressure", per the Twitter policy? You bet. Does the NPR model naturally align itself to bigger government with more grant-making power? Definitely.
I think Twitter could have come down on either side. It's a grey area. But how could the NPR story fail to mention the $465 million?
See also https://www.npr.org/about-npr/178660742/public-radio-finance... where NPR makes the opposite argument, namely, that "Federal funding is *essential* to public radio's service to the American public and its continuation is critical for both stations and program producers, including NPR."