In the OZ forces, up to a point some years ago (but prior to my retirement!), if the commissioned retiree served through to retirement age, he went on to the RL in the next rank up, presumably unless some nasty type had blacklisted him.
Now I can't say that we copied everything that you lot did/do, but between the wars you might have thought so. Best explanation I can think of.
Edited to say that I found the thread on RAF retirement after I had posted this. Seems similar to our now defunct set-up.