That would be a shame. When I was a Sea Cadet I attended several summer training sessions at NAS Brunswick and it was very pleasant. A really nice little base.
There is still Coast Guard Air Station Cape Cod, located on the Massachusetts Military Reservation along with Otis Air National Guard Base. CGAS Cape Cod has helos only, if I recall correctly.
In New England I believe CGAS Cape Cod would be the only active duty air station if NAS Brunswick closes.
Nope, the Coast Guard also has their fixed wing aircraft there, just in different hangars.