I'm glad to see this topic popping up now and then, and thanks to SA for starting it as it can be a delicate and painful topic.
Two thoughts:
In a way, I think its good for us (both for the guys and the ladies) to have to deal with this issue now and then as it brings home the point that, for the most part, these are "artificial" relationships. I dont mean that in a negative way, but these relationships dont start the way normal relationships do and we need to be reminded of that now and then. I suspect many of the ladies may have some feelings for some of their clients but its just easier, emotionally, to "drop off the grid" and move on. I suspect that most of the guys respect that, and its great when the lady sends out a "goodbye" message here. To Angela's point ... heck ... there's no reason why the ladies shouldn't be able to keep in touch if they are interested. If there's enough interest in that, maybe there could be a forum open only to the ladies for the retired SPs to keep a conversation going.
That being said, its an undeniable truth that friendships develop in the middle of these artificial relationships and that can be a pretty confusing. And I bet in those situations, the people involved manage to keep in touch. If they dont, we shouldn't take it personally, and we should always assume their "better angels" are leading them away.