We'll see...  People have been discussing this for a long long time.  The big problem for me is how would they know who has even used Metamask vs other wallets?  That leads to them likely airdropping their tokens to users who have used their token swap function, which I doubt many people even use because there are better options available.  This likely means that people who are playing games to get more airdropped tokens likely will, and the rest of the metamask users will be left in the cold wondering why they've supported a wallet for years who just skipped over them with their airdrop.  Maybe they have better methods of identifying users that I'm not aware of, but I think this is going to be a disaster and more of their users will be pissed off they got skipped for the airdrop than users who are happy with what they received.