When I was a good churchie, my assumption that he would return was mainly based on that LRH ED when he said that he would work with us here until we got the planet clear (whatever that meant), then go off with us to "Target 2" and clear that one, and so on until we had got the whole universe back up to native state.
On top of that I assumed that although he could of course pick up some adult body and come back a day or month after he dropped the previous one, he would probably wait the right number of years to make it look like he had been with a particular body from birth, maybe 18 or 21. That would be the most sensible way to do it PR-wise, as although reincarnation is a bit unreal to many in the west, it's not as unreal as taking over a body aged ten or twenty.
Those were my thoughts then. My thoughts now are:
1. He pretty much lost it in the last few years of his life, and is unlikely to be piloting his life this-lifetime with full recall of his prior life.
2. If he did have such recall and comparable ability to last lifetime, by now he would have worked out a way to reclaim a good chunk of his accumulated wealth from then. I know that legally one cannot maintain assets into a later life, but minor considerations like the law didn't seem to stop him before.
Paul