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, at least with this wallets which I know about:)