The attack is just as important as the release. Depending on the type of sound you want to come out, you need to have a correct attack, which may involve distance above the keys. For example, to play very quietly, height above a key is useful, since you can put your hand into a slow motion before the keys is pressed, and then retain that same motion after contact with the key.
The release is connected to the attack. Consider the difference between pressing a key and releasing it (something like using the accelerator pedal of a car), and pushing off of a key as the release (something like doing a standing long jump). The latter can provide awesome intensity in your music, much more than the former. Pushing off leaves your hands in the air, with great position to attack the next notes.
Some have called this type of movement emotional or theatrical. Sure. But it's real purpose is to put life into your instrument. To make the piano sing, you must let it become a part of your performance. How can you do this by keeping your hands solidly on the keys? You cannot. The reason professional pianists do this is not for theatrical value, it is to make you involved enough in your music so that others can understand it. Take, for example, Yakov Kasman, who won 2nd place in the Van Cliburn competition. In this video he lifts his hands all the time. I saw him in concert stand up multiple times while he was playing because that is what the emotion called for.
So, yes, lift those hands if you want. But always hit the right notes.