1. The notice says, "please call United reservations."
2. My advice would be to call United reservations. Could be good news, bad news or no news. But, if you don't call, you won't find out and you might wind up watching a lovely view of your aircraft pushing back with you sitting at the gate watching.
3. Sorry if there's a long hold time, but this isn't an itinerary where there's exactly hourly service if there's a problem.
4. Let us know.