Do you remember the last time such a thing happened? It didn’t go so well for the side that tried to secede. Why would it be any different this time? What would “the US” have to gain by letting Hawai’i leave the union? Which state would be next?
The first rule of US club is you don’t get to leave US club.
I would say there is some difference between contiguous states saying “Fuck it, we’re going” and a state that is 2,400 miles from the mainland petitioning for some form of sovereignty. I think the cession of the Panama Canal Zone (or even the independence of the Philippines) are closer analogies than the Confederate Rebellion.