Steps to reproduce:
1. Create a project. Set length to, say, 600 frames.
2. Turn on camera record mode.
3. Set keyframes for camera movement, e.g. one on frame 1, the other - frame 590.
4. Play the project to confirm the proper camera movement.
5. Go to project settings. Change project length to a shorter one, say, 500 frames.

When you play it back you will discover that camera still moves the same way. The expectation is that any keyframes that are outside the new boundaries would be cleared, but that doesn't seem to happen.

I wanted to use an older project as a starting point; so I opened it, saved as a new one, but I needed a much shorter animation, so I set the new length and got everything set up only to realize that there was an unwanted movement. I searched up and down checking every single keyframe - to no avail. No matter what I did, I couldn't get rid of this movement! I was pulling my hair out for an hour until it dawned upon me to check outside the project boundaries and discover a keyframe just outside the boundaries.

Same thing happens with transform keyframes. I just checked.
I do not know if this is by design, but it would sure be nice to have it addressed. In the very least provide some sort of a warning or an explanation.