That it will happen, and that future airdrops in total will be 14% of the original mint. That using Optimism in positive sum ways is likely to be rewarded. As of June 5th, 2022 we don't know any more than that.
Even when a decision about the airdrop happens, it will have to be confidential until after the snapshot is taken. If we disclose the exact criteria, or the snapshot date, a lot of airdrop farmers and are going to try to get in on the action. We prefer to avoid that and distribute the tokens to bona fide members of the community.
However, in addition to Optimism airdrops, there are also OP tokens distributed as part of the Governance Fund. Some of the recipient of these tokens plan to distribute them to their users.