As I can see Zapier does not have a Delete Record action, but you could update to delete the email or all the fields. Also, note that you’d need a Pro account, because you’ll need 3 steps: the trigger, find record, and update it.

You could do it better with Integromat that has multistep in the free account, and also a Delete Record action.

I agree with @Elias_Gomez_Sainz. In this case, it looks like Integromat would be better. You can easily make the workflow he suggested:

3 steps: the trigger, find record, and update it.

This is what it would look like:

A bit late to the party, but we've built a platform, Syncgrip, that will allow you to sync your Mailchimp contacts and Airtable records (including unsubscribe events). And it takes <5mins to setup

Here's a short demo of it in action: https://youtu.be/fxegMUymY_E?t=1815 (taken from a recent appearance on the BuiltOnAir podcast to showcase Syncgrip)

Check it out here: https://www.syncgrip.com/