I wasn't aware it was possible to have the crop tool default to any specific aspect ratio. It has always been my understanding that the tool always defaulted to the aspect ratio of the original full-sized image, and that it was necessary to select any other aspect ratio desired. At least that is always the way it has seemed to be on my computers.
I don't know HOW I got it back, but if you look on the ends of the crop area where it says 4x5 there are lines that indicate the area which will be cropped out when printing. I may not have used my words right but this is what I want to know how to save because every Lightroom update somehow destroyes this and I have to bumble my way through to get it working again.
Don't know if this is what you are referring to are not. When the crop tool is activated you can press the O key to toggle through the different crop overlays that are available, and aspect ratio is one of the overlays that will display.