@jumbletumbles My D is a freshman at Miami, so I can only give you a parent’s perspective.
Washer/Dryer - D’s complained that the dryer cycles aren’t long enough. She often makes use of her folding drying rack. She has not had issues with the notification system.
Mini Fridges - work ok - not great. It took D and her roommate a bit to figure out a setting that kept food cool without freezing it. They do keep milk, fruits and veggies in their fridge. I wouldn’t recommend anything such as ground beef or chicken. Her dorm has a kitchenette on each floor with a full size refrigerator and freezer. Her friends who like to cook do store food in the big fridges.
Bikes - D went to campus without a bike, then called a few weeks into the first semester and asked us to bring her one. She doesn’t normally use it for getting to classes, but it’s handy for getting to the rec, health center, etc. that are a lengthy walk from her dorm. Riding to some classes could be tricky because of the number of people walking, but you will see many full bike racks outside the academic buildings.
Window AC - just depends on preference. Ohio can be pretty toasty in August. My D has allergies, so she requested a unit. However, she ended up in a renovated dorm that has AC. If you plan to request a window unit, do so soon. They only have so many units and do run out.
Cable - D doesn’t have a TV, but many of her friends do.
Coffee - My D could not live without her coffee maker! She has a single serve coffee maker from Bed, Bath and Beyond. It is not a Keurig and uses regular ground coffee (so no expensive K cups.) D has early classes every day and does not have time to go to the dining halls in the AM.
Vacuums - D has never found the vacuum in her dorm. She bought an inexpensive corded stick vac at Target and uses it frequently. If you think your son will use a vacuum, I would recommend getting one.
Ds best dorm room purchases were probably plastic drawers for under her bed (she has a mini lofted bed) and a hutch for her desk - both from The Container Store. She also has a metal cart that her fridge sits on. It has two shelves for dishes, snacks, etc. We purchased the cart at Bed, Bath, and Beyond. A nicer (and more expensive one) is available at The Container Store.
Bean Boots and a warm parka were also fantastic purchases. Not sure what boys wear, but don’t wait until winter to shop.
Hope this info helps a bit. It would be interesting to hear from a student!