There are several really tall buildings (at least 6 that I can think of) as POIs and some large, spread out ones (like the football field). I'm sure many more POIs will be added before launch. They add some new/redesigned ones every release or so.
A20 should include a much better RWG engine so the options will only get better. They already have mini towns that include several related POIs, like the old west style one, so the college campus could be possible. You won't likely see underground POIs added back yet because they are a nightmare for SI, but maybe before release from what I've read. And the only way you will see trains with tracks is if someone gets inspired and finds a way to make roads way better and then can easily convert that code into train track generation.