If you look at the 5-day chart for southwest, you will see 2 big drops that correspond to Monday opening bell and the faa announcement. https://www.google.com/search?q=southwest+stock

But the reason why I'm not a day trader is that I have no idea why they rebounded so quickly haha

Traders operate on all kinds of time scales, and most trading is done based on algorithms that account for the fundamentals more than of-the-day news. It's likely that holding SW is good for the long term as people make more money and continue to fly more.