No need to contact anyone! Once you've joined the eGO Community, you're part of all division. The tag under your forum name is only your primary division and is considered your home. Although you are family of all the divisions!
-Allan
This is exually wrong, the DL's mostly appreciate it if you let thim know you are switching. Not sure if this is only for admins or not. But I recommend you to contact your TF2 DL and tell thim you are switching Divisions.
~Bird.