Because your email is also how you log in (see Logging in with a one-time code), changing it is a verified action rather than a plain edit:
- In your account settings, enter your new email address.
- We send a 6-digit code to the new address.
- Enter that code to confirm.
Your old address keeps working right up until you confirm the new one, and you can see the pending change and cancel it at any point before you do. Nothing switches over silently in the background.