While I don't find the referenced RR particularly illuminating, I think they are saying that if terms are rehired then they're not going to forfeit so there is no partial termination. (It doesn't seem to contemplate that they might take their money immediately and in fact forfeit, but I don't see the need to look for trouble.) I see it as general guidance - but don't see the relevance to sale of a business, closing of a plant...unless of course they are rehired, but those would appear to be highly unusual circumstances. I mean if you sell a business, you're probably going to terminate a plan associated with that business and 100% vest everyone anyway. Are you theorizing about un-selling a business? If a business is sold in a stock sale and the plan goes with it, then I don't see terminations and rehires happening.