We definitely will NOT be leaving Halo PC/CE. Nothing there changes.
As for Forge, it is my understanding that initially there will be only personal hosting off your Win10 PC, similar to how you can host a Halo PC/CE multiplayer game from your personal PC (if you can figure out the port forwarding). So the only "admin" would be the person hosting from their PC, and I'm not even sure what commands they would have available to them. We'll all learn more about it together once it is released.
Until someone figures out a way to run dedicated servers (like we have in PC/CE), I don't think we'll be doing anything in the way of official clan servers for Forge. But we can certainly play around with personal servers and maybe organize some games on Forge.
And L4NC3R I'm sure there will be quite a few people who don't have the hardware/software to run Forge (requirements
) so you won't be the only one not playing it. But for those who can, it will be an interesting new experience.