Why because it is, who ever heard of changing the venue of a game just so it is a more hostile crowd which I am guessing is the Islanders motivation
There could be a couple of reasons:
1) Tickets weren't selling in Brookly and tickets in Nassau would.
2) They want a more hostile crowd.
3) They wanted to make it more difficult for the Leafs fans to travel to and get tickets.
4) They might be shifting other games to the Coliseum as well.
5) They wanted to make Tavares happy by giving him at least one more game at the Coliseum.
I don't care what the reason is. More games at the Coliseum is a good thing at this point.