Is the proposal has been approved yet?
It's in RFC (Request For Comments) stage, yet to be posted in Osmosis governance.
If the snapshot has done than there are so much people who cant participate in this airdrop
since it is already happen but why i didn hear any news from the big exchanges, because usually they will take participate in any kind of airdrop
Regarding snapshot it's mentioned in proposal.
A snapshot date has not yet been decided, but it will be after the publication of this post
You will hear from exchanges once the proposal has passed.