Absolutely nothing new in this - seen it several times before with other companies. In fact, it seems to be par for the course!
One guy I knew (still know!) was the rep on the Staff Association (we didn't have a union) and ended up as the Ops Director when the company was taken over and several of the Board jumped ship to start another company (no names, no packdrill!!).
As they say, be nice to the people on the way up because you never know when you might meet them on the way down.
I don't think that this type of progression means too much in terms of ability but you do get to meet the management on a regular basis and hence it is not too surprising that if the individuals are perceived to be the right material they are offered a management position.
Finally, remember the "Peter Principle" that people rise to their levels of incompetence. This certainly seems to be true with some airline managements that come to mind. Poacher turned Gamekeeper?