Yes, they ideally should - this change seems innocuous enough but for clients that haven't encountered email-less ACME account registrations before it could still have an impact if you use the registration result and expect a value.
The client I develop is currently seeing a few thousands failures per day as a result of the recent API certificate type changes resulting in different client cipher suites being required: Certify the Web Cannot create secure channel error but again that type of change should have been ok, it just turns out it wasn't in reality.