They vest (or laps) over the 5 years following retirement just as they normally would. At least that's how the program was presented when the whole RSU s where implemented.
That's why I still post on BC in support of UPS three years after leaving, I started reserving 20% of half my effort every year in Restricted Work Units, and now as those RWU s laps, I work them here. Seems fair.
@misterjingle/hoax/monkeybutt must have held back a boat load of RWU s.