I see what you mean, but I'm not sure if I entirely agree.
If the sale fare at the currently available fare bucket was indeed so good, then it would've been sold out very quickly regardless of CR+, as people would just buy it with cash.
I guess if the expectation is that people will now use CR+ to buy tickets that they otherwise wouldn't have bought with cash (as is often the case for premium CR seats), then no, that's not happening. That's just the same as releasing more CR seats (which they evidently don't want to do).
I suspect from QFF's PoV, if they can make CR+ as attractive as cash (but not more attractive like CR, or less attractive like P+P) to purchase "any seat" for customers with large points earn and balances, then that's a success - it means these customers can start using their points on regular tickets without complaining about lack of availability (CR) or very poor value (P+)
Also if the seats are immediately getting sold out, then you could also argue that CR+ is a failure because many people will struggle to get access to these reward seats, which is the issue they're trying to fix in the first place.
Obviously for those of us without 7 digit points balances who are looking for a significant increase in value over cash fares in premium cabins, this doesn't achieve that.