What is frustrating is that we are all hearing or experiencing different things.
Certainly terminology may be part of the issue. I asked to change or cancel a ticket not to void a transaction. Although to cancel a ticket in the circumstances I describe, fits the definition of 'to void'.
My travel was for April 22 so I was nowhere near the 22 day limit. And I was proposing to book the reward travel, immediately book the revenue tickets and was just asking if I could cancel or change the reward tickets if I couldn't get the same seats on the revenue ticket. The answer was no, I couldn't do that without activating the $90/ticket change fee.
I was also frustrated because the flight choices coming up for reward travel weren't the same as those for revenue. For instance, one was a routing via YYC that would work well for us because on a 2 x 2 plane we don't feel the need for upgrades to exec. But that flight wasn't showing as a revenue choice and I had no idea how much that routing would cost. Would it be dramatically more than the $205 T+ or $624 Lat fare on the more direct routing?