I don't watch soaps, but I do know from past experience that when a cast member leaves, they become a 'non-person' - they are never referred to again. No-one wonders where they are, how they are, and they are never ever in touch with anyone left behind.
There are a very few exceptions to this rule, but it is a standard for all soaps.
So, when you bring people back, is anyone in the current cast interested in why they have disappeared off the face of the earth for twenty-plus years with never a card, or a call, much less a visit?
How did they work it?