They did. But what they can't do is make a list of every change that might cause issues in a custom scenario because that would depend on the custom scenario. In a custom scenario I could make the sky blaringly bright pink by setting the color code to 10,0,10, and then there could be a game update that changes the sky rendering and causes a crash if the color values are set above 1.0. The developers would have no way of knowing that I had set the color values above 1.0 so they would have no way of knowing they would need to warn me. They do a good job of listing major changes that scenarios need to adapt to, but literally everything in the update notes could potentially break a scenario and they have no way of knowing what, if anything, will. It's on you and I to read through the notes and look at the changed files and determine what applies to our specific scenarios and make changes as needed.