Yes, just to clarify what John is saying we are going to be contacting designers with scenarios uploaded at the CS H2H to see if we can help them in anyway, while it is indeed the responsibility of the designer to post for testers and follow up on feedback provided John and Ed are also here to try to grease the wheels of the H2H test system for designers to help smooth the path to seeing these scenarios be approved. :)
So
nothing will be removed without the designer being contacted and if you are a active designer with active tests then you have absolutely nothing to worry about.
But i have to say their has been in the past designers who have uploaded scenarios and then either not bothered to get them tested or just lost interest, in those situations we would be looking to free up space on the test page for new scenarios by removing these (having of course spoken to the designer first). ;)
I hope that clears things up.