This will delete all your data, including channels, videos, comments and you won't be able to create another user on this instance with "<x id="PH" equiv-text="this.user.username"/>" username.
It will delete {count, plural, =1 {1 video} other {<x id="count"/> videos}} uploaded in this channel, and you will not be able to create another channel or account with the same name (<x id="PH" equiv-text="videoChannel.name"/>)!