While it is a really cool plan, and I would love that type of aggressive urban planning, burying the highway does not seem feasible.
The Big Dig in Boston, while a 3.5 mile tunnel, started planning in 1982 and was supposed to cost 2.8 Billion Dollars. It was completed in 2007 and cost over 14 Billion. That is the most expensive highway project in US history and it did not go smoothly, to say the least. it will not be paid off for like 20 more years.
I cant image that federal and state investment in Buffalo, where the need is not absolute. (to service a football stadium and ancillary gains). Boston did it to ease traffic congestion and find more space above ground for construction and green space. It was more a of a necessity.