Your reasoning is completely opposite to my experiences in working with nursing homes and hospitals. I have never seen any facility refuse to pursue speech therapy (they do the swallow evals and treatments) for fear of liability. In fact usually it's the opposite, they try even with patients where there's not much hope. As I said, it would take a tremendous conspiracy to deny someone with the ability to swallow an attempt to feed orally.
Or perhaps, an abusive guardian who would fly into a rage if he discovered such things were going on, as nurses have testified.