This rumor is already aged. For me, if this will happen, for sure the worth of their airdrop is not that really huge, like the total amount of it in $ per person that got the airdrop.
And even though there will be an airdrop, for me, there will be some qualifications, not all metamask users will able to get the airdrop.
Metamask is the #1 wallet for Ethereum and other chains right now, so expect that this airdrop is gonna be huge and that will be a challenge for them.