To the first part, I would say: what market? If you're located in the central NY region, sure there's value. I don't know if it's a million a year, but it's substantial - if you're located there. If not, I question the value of just having the name mentioned on a building you didn't supply AC to (a source of jokes, per #48, below) located in a region you (mostly) pulled out of. But that is a business issue - way beyond my ken.
As to the second part, you're probably onto something. We're all speculating without the agreement. But based on SU's recent conduct, the deal may only involve a building (physical) label arrangement ... not a "naming rights" agreement in the modern sense requiring "Carrier" to be mentioned (synonamously) with the Dome.