It's such bedrock infrastructure that I've seen it used as fallback in the event of electronic trading infrastructure outage, brokers would accept specifically formatted emails as orders.

At this point it would probably be less impact to have phones go out globally because people would fallback to walking across the floor, using zoom/slack for simultaneous communication or email for more async.

I don't expect a fundamental shift but the boss having no access to his mails certainly seems like something I would bring up quite a bit.

Barring corona & year end holidays, this is probably the closest we can get to a global work holiday.