No, that would be a bad precedent. Simply "not cooperating" with the feds shouldn't be a crime. Think about how that would play out someday if the feds decide to come for our guns.
2A is unquestionably a part of the Constitution & refusing to cooperate with an attempt to infringe on that is quite different from the highest legal officer in the State of New York refusing to cooperate & ordering other law enforcement officials in NY not to cooperate with Federal Immigration officials enforcing Constitutional Established Federal Immigration Law. The NY AG does not get to choose to ignore Federal Law. She is quite literally harboring Federal Fugitives in violation of Federal Law and unquestionably Obstructing Justice in the Federal Apprehension of these fugitives.
I will add to that that NY Gun control laws are some of the most restrictive (and quite arbitrarily applied) in the US and unquestionably infringe on the 2A and, as the highest law enforcement official in NY, she is in violation of the US Constitution by enforcing them. The AG of NY will come for people's guns long before the Feds will. That is a fact.
Better to nip it in the bud now, before they get any bigger ideas, put this Sanctuary City bullshit before SCOTUS now & have them declared unconstitutional in the next SCOTUS session. Hopefully the RBG situation will be resolved by then.