Not true, at all!
The remaining insulin can be removed from the pod through the fill-port. About 5-10U remains inaccessible, and must be discarded. You do not need to waste any more than that if you have a pod failure.
As for normal operation, I always run my pods dry – that is, all the way to an Empty Reservoir alarm. As a matter of routine, I use every drop of insulin I get from the pharmacy unless I have a pod failure.