Moving Quick, Again

We just found out that more of our neighbors are moving. New York movers will be here on Monday to clear them out. What makes this, and the previous three moves, so strange is the fact that we find out about the move 3 days before it happening. This one is at least going on at a normal time. The last three all moved out at midnight, and only 2 days after they told us they were moving. We just moved here, and we gave all of our neighbors a few months notice before moving. I'm just confused as to how you keep it a secret for so long and then just up and move? Or is it just as surprising to them as it is to us?