Another possibility is that they meant to ask "would you like to be moved to...?" and something was lost in translation. That has happened to me, once with an offer to change to the date I would have chosen myself, had the fares at the time not been much higher!

If the flight is operating and you show up for it in time, they should put you on it. So you might want to take this as a wake-up call to get there really early, since it's so overbooked that they're dialing for bumps.

Also, if your miles came from enough flying for you to have elite status, you might want to call that desk to find out what's really going on. Unless the entire plane is full of elite pax, hardly likely to such a popular vacation destination this time of year, status should count for something when they decide who gets on and who's left behind.