Is it I understand correctly?
When someone want to change his email on BTT account,then he can't use his/her account for those 7 days because "The account stays locked throughout all of this.
No, the queue only applies when the administration changes the email address, not when you change it yourself.
It's for recovering hacked accounts and similar. Most people don't need to care about it.
Is it the new year resolution for 2019? Because hacked accounts are usually never recovered