It’s not an easter egg. We really don’t want people to be able to register new epizy.com subdomains because the domain has been used too much and is having too much issues. It’s been hidden or removed as well as is possible, but yes, it’s not completely impossible to create new epizy.com subdomains.
However, know that by doing so, it should be considered an exploit, and we may choose to implement measures against “hacking” like that, which may give you trouble.
So please don’t do this.