So Binance will support the snapshot right.

Which exchanges will support XYM ?
This link should be one to follow I believe:
https://symbolplatform.com/xym/From exchanges I care about, Poloniex support both opt-in and listing of XYM and
Bittrex doesn't support anything regarding airdrop so far...Bittrex is a dead exchange, they just haven't realized it yet.
Well, maybe in general and on long term - from XEM point of view at the moment, which should be relevant for airdrop of XYM, Bittrex with 111 milions XEM seems as alive as Poloniex with 94 milions:)