Good question. It's hard enough to get an upper-manager to take a phone call, let alone review "the process" with us. But think of it this way: the process is the ONLY tool management has to proactively run the business - they should be happy to do this! I know that isn't always practicle though.
I favor a "rotating strategy" where we cycle through the process at monthly meetings. So in January we review, say, the processes associated with Project Management. In February we might look at software development. And so on.
Upper management doesn't HAVE to provide feedback, but it's much better if they do. After all, these are the "levers" we need to successfully run this business.