YXZ order from the video does not work in Blender because it uses the
Z up axis convention, whereas Maya uses
Y as up axis.
If you want to get a setup like the video, where the gimbal lock occurs when looking up or down, you need to parent the camera to an empty and rotate the empty
90° on the
X axis, then set the rotation order on the camera to
Only changing the rotation order on the camera can't work, the gimbal lock always happens at
90° on some axis and the camera is at
(0°, 0°, 0°) when looking down, so this extra parenting is needed.
That being said, I think the standard
XYZ rotation order in Blender may actually be better for cameras. It will give you gimbal lock when tilting the camera
90° sideways, which is perhaps even less common than looking down or up.