I lost my Discord account for daring to use the "change your e-mail address" feature. Nothing warned me that this was a potentially-destructive action. It happens.
A year or two ago I went through every online account I have to change the email address.
I should have kept a record of results. Some were good and easy. Some had no option other than an account closure. Some involved a single contact of support without any real verification that I was actually the account holder. Some involved a protracted string of contact with support that tried to claim I was asking for an impossibility. Some services kept my old email on file and I periodically receive something to my old address.
I had way too many successful email changes that did not send an email to my old email account informing me of the action. If a hacker had stolen those accounts, I might not know for a long time!