It depends per school, but 4th year students usually fill their own schedules with electives and rotations. You can definitely fill it in a way to make it as in

It depends per school, but 4th year students usually fill their own schedules with electives and rotations. You can definitely fill it in a way to make it as intense for the first three years, but it would likely cause students to start burning out before residency instead of during it. I am currently on my 4th year rotations and I find them to be some of the most educational, important, and interesting ones. YMMV of course