Hi Kumara,
Unfortunately for Method:Classic - this is a feature we arent looking to implement. Moving forward our Development resources will be focused on Method:New, but we are of course still going to be supporting and fixing any issues that come up surrounding Classic - Just not adding any new features.
That Being said - this feature has been implemented in Method:New. Removing an activity (or making it internal at a later date) will remove the Activity from the customers portal.
Thanks Kumara.
Regards,
Ben