I think that's a lot of the point here. They won't be starting with that customer base if most of that customer base leaves because of these changes (which I think a significant portion of them may).
Yes, as I recall, when Rackspace ruined Slicehost, a lot of people moved to Linode. I am guessing the same thing is likely to happen to Linode now. I'm just not sure if there is as clear a choice for a new company as it seemed to be when a lot of people moved from Slicehost to Linode.