I agree with JoePah that bike theft is an issue on any college campus; however, as someone who bike commuted for 20+ years, the only time I had a bike stolen was when I didn't use a hardened U-Lock or one of those super strong Abus flat steel folding locks. Never depend on a cable lock for serious protection. For my long stops while working at a local junior college, I used both a U-Lock and cable lock. The cable added a little extra protection for the wheels and meant a thief had 2 locks to break. That extra second or two can be enough to deter most thieves.
Did a couple of searches for upright style commuter bikes & city style bikes on the main EBR site and there's a lot that would work. Plug in what features you want into the expanded search options to see a lot of choices with reviews. Remember, some come with a lot of the accessories that are handy for commuting, like a rear rack & lights but not all and those are not expensive to add on. If your son wants something that's a hybrid between road and trail use, re-run the search. Many hybrid style bikes with slightly wider tires would work and again, racks & lights can generally be added.
Just quick thought, Juiced, Easy Motion (EMotion), Raleigh, Specialized, Riese and Muller all have good quality bikes under $4K. Differences will be in motor size & power output, accessories, etc. Since the college is located in relatively flat terrain, your son may not need a big motor for adequate support. I imagine it's the books & computer & other stuff carried in saddlebags that will add a lot of weight, so he'll still want good power & range. Remember, he will be riding this bike other places than just around campus; Ann Arbor is a great college town.
. An ebike provides many more options for range than an escooter does and there's a bit of exercise that goes along with the pedaling.
