Yes, they really can sway backwards, but it depends on just how you define "backwards".
In this case, the palms are a symptom of a weather front. Up North from Boston to North Carolina, they've gotten significant snowfalls. There are road closures all over the place, it's generally a great day to stay home all along the Eastern Seaboard of the United States.
Here, the result is that as the front came through over night, the temperatures held steady until the morning. We had some light showers, or rather showers that weren't heavy enough to wake me or the dog. The roads were covered with a sheen of rain water, and my car that I carefully washed the day before now has water drops on it.
That's what I get for leaving it out of the Car Port to serve as a Tourist Block for my driveway on a Bar Night.
It is windy now, and quite grey. Most of the homes around here of this vintage have jalousie windows. Get too close to one on a windy day and you'll learn why they get replaced. I was standing in my laundry looking for some items next to the door and I felt the breezes coming in from outside. Those windows are not very efficient at keeping the weather out, but in an area where power outages happen frequently and the majority of the time you're trying to keep the box of rocks cooler than outside rather than warmer, they're frightfully practical.
Instead of sitting on a beach, in the sun, watching the palms overhead, from a hammock, I'm indoors on a big green chair looking at a patch of areca palms that are leaning toward me rather than away in the breezes.
It could be worse. I could be trapped in a hotel in Dumfries, VA near Washington, DC. It is a long way to drive in weather like they got up there and while it is only 3-5 inches of snow that was predicted. That was yesterday and now the total accumulation predicted to be around 9 inches in DC. If you extend your travels south to Raleigh NC, they're predicting up to 8 inches.
I've driven in bad weather down I-95 before, a number of times. It was always a bad choice. One car hitting the snow will compact it more and more until you get a corrugated washboarded road bed full of ice and treachery.
To get below the Snow, you have to travel to South Carolina and then you find Ice.
So palms swaying backwards are not so bad. It will be back to normal for the New Years Weekend. If you're already here on vacation, enjoy. Just don't laugh too hard at us Floridians. Our blood has thinned to water.