New to me GP100, question about cylinder release

Just bought a used gp 100, the weapon was made in 1996. While studying up on the gp 100 I watched a YouTube video, the guy was demonstrating how the push button cylinder release would allow the cylinder to flip out, like it was spring loaded. Is the gp 100 cylinder supposed to pop out when the release is pushed? Mine doesn't .

No. You are fine.
He was probably using his finger on the backside to push it out.

Might have been tipped, so gravity was making it fall open.

No, it won't simply "pop out" (like ejecting some magazines from an autoloader). I don't know of any modern revolver that the cylinder will rotate out automatically when you press on the cylinder release. What should happen when you press the cylinder release, when the gun is being held normally, is, well, nothing. Then when holding the cylinder release button in, if you tip the gun to the left, the cylinder should rotate out of the frame.

DO NOT push the release button and flip the gun violently to the left to have the cylinder come out, this just causes undo wear on the crane and frame. Just push the cylinder release with your right thumb and bring your left hand around the frame, use your middle one or two fingers to push the cylinder out of the frame and hold on to it. You can then release your right hand to get your reloads while with your left thumb you rotate the gun to a vertical position and press on the ejector rod to empty the cylinder. Bring it back to a position to do your reload, then grip the gun with your right hand and close the cylinder with your left thumb.

If you happen to be left handed it is bit different because the cylinder does come out to the left. Actually I think there is a revolver made that the cylinder comes out to the right but I can't think of who makes it off the top of my head.

YouTube, at its best, can & does disseminate much helpful info.

Unfortunately, the rest of the time it can cause actual injury & damage.
Never believe what you see there is gospel, always double-check, as you did here.

In this case, think about it- in looking at your gun, do you see any signs of any sort of spring mechanism that would pop that cylinder open when you push the button?

It doesn't close under spring tension, it doesn't open propelled by any spring.

Also- DO NOT FLIP THAT CYLINDER CLOSED!
Just in case you saw it done on TV, in countless movies, or on several YouTube videos.

Close it with your off hand.
You don't have to baby it, but flipping it shut is also bad for the crane.
Denis