I think this would be fairly straightforward.
You’d want to take advantage of Webhooks and trigger on a CMS update.
Within Integromat, you’d filter for that specific ‘switch’ toggle value. If it exists (and is set to what you want) you allow the Scenario to continue and pop off an email. If not, it stops there and no email is sent.
Happy to go into more detail if any of that isn’t clear.