Surely encouraging people to do this fits precisely with how the airdrop and Ethereum’s Phoenix are supposed to work. What better public good to incentivize for the ecosystem than getting more people to stake themselves (whether with a minipool or solo staking).
With that in mind maybe this would be better for an airdrop nearer to when withdrawals are enabled for validators on the Beacon Chain, with the plan to issue some rewards on the same basis in the future. That way people who are currently using CEXs/Lido to stake would see home stakers be rewarded and be able to withdraw their funds from centralized services, set up their own validator and expect a future airdrop for doing so as a way to overcome the friction of effort it entails.
EDIT - … but I don’t have any idea how many people with >16 or greater than >32 ether use centralized services and would therefore be targets for this.