As raised previously (e.g., The default image insert action) I think for many people it is vastly more common to add images from the library rather than via a live in-app camera. I suspect people are bimodally distributed: some almost always use the in-app camera, and many literally never use it.
Given this, it would be extremely valuable to be able to customize the order of options in the insert-image button on the new formatting keyboard – in particular to be able to change the top item from a camera to an image picker.
One alternative model could be that that button always shows on top whatever action within it that you took last. Then it would immediately adapt to the given user’s workflow.
As it is, I find it surprisingly high friction to add images to notes on iOS, and every time I accidentally activate the camera is disruptive and frustrating. I am very confident I will literally never in my life want to do this, but I add images to notes (most often “scans” of handwritten material, captured and cleaned up outside Bear) frequently.