Meta App Manager, How do I disable a Beta channel without deleting users?

Hi,

I have the Meta App Lab beta channel that I no longer need for the time being.  I want to disable the build that's on there such that no one can use it but I don't want to remove the users that have signed up already for it.  What's the best way for me to achieve this? 

Does deleting someone from the invited users also delete the app from their device?