Yes I know Tufail uncle, he was my father's IP at the Academy and on F-16s. If passions were that high, they would have done it. It isn't in their culture to pursue such big goals after retirement. They are more than happy to pen down books about their experiences in the service. And as far as opportunities are concerned, they are the only ones who can push the spark for it. Almost all don't consider it. So far I only know one, he was also asked to fly a MiG-21 in the US a few years ago but COVID came into effect. Their interest for that might be high, but passion probably not so much.
A few years ago I had reached out to a former US Marine General who flew private Harriers around airshows. We proposed a few F-6s in PAF colours to which he was keen and asked for ex-PAF guys. But none of them were interested in pursuing it.