Let's not kid ourselves. There will be future RIFs as a bi-product of all of the consolidation of business units. That won't happen on 1/1/19. It will take time to figure out who does what and how many of the remaining people they need to do it. This volunteer package may be all that go right away. After that, there will be a bunch of political posturing going on internally to try to land at the top of the heap. I'd bet a summer 2019 RIF at the earliest but more likely by next Thanksgiving.
Excellent point by @W0CiWFB-uos.