X now requires code from existing email for email changes

Usually when you try to change the email on your X account, a code is sent to the new email for verification and that's it. Now X will send a code to the current email on your account as verification before you can be allowed to add a new email.

This has an advantage as well as a disadvantage. Lets say someone gains access to your account, changes password and tries to change the email, they will not be able to because X will require a code from your current email. Since they do not have access to that email, they cannot completely make changes to your account. Which makes it easier for you to regain access as your email is still linked.

However if you lose access to the email on your X account, it will be impossible for you to change it to a new one because a code will be sent to your existing email (Which you can no longer access).