Helping people leave your App isn't the the top of most product manager's goals; even without the managment nightmare.
Utilising inherent network effects to aid discovery within your app is the top of most product manager's goals.
Not allowing URLs is neglecting one of the fundamental pieces of the World Wide Web, no matter what product manager's goal is to line is swimming pool with gold.
A hash character I guess can be used but they don't do anything.