Only D'Antoni was gone because of Melo.
Woodson and Melo were very tight. Phil let Woodson go because Woodson had no knowledge and experience of Triangle or Phil Jackson's cultural beliefs.
Fisher was about a young guy who just didn't understand the coaching game quick enough on the fly. The Knicks want to win as many games as possible and definitely make the playoffs next year. They could not keep on waiting for Fisher to grow as a coach and not make mistakes that he was showing repeatedly he was making (Although I am not sure that Rambis will do all that better in getting wins).
Rambis is about closing the season out the right way for the Triangle, the offense, KP in particular. As we saw last night, KP was right away yanked out when he was not posting up or playing good man defense. Rambis will put the onus on KP to have better shot selection and to play better man defense. He will also run the offense consistently. I don't think he'll be back next season as head coach, unless the team wins more than half of their games with his as the head coach. I think they'll either bring in Walton or Shaw as the next head coach with Rambis returning as the associate HC.
So it's not about Melo - Melo from what I've seen only got D'Antoni fired. But others didn't like D'Antoni on the team as well. Seems D'Antoni even had the same problems when he coached Kobe, Dwight, Pau on the Lakers.