From what I have read (Prof Karol Sikora one interesting source) it seems very unlikely we will get another peak like this.
Hopefully you are correct. But universities would be very foolish to make assumptions at this stage about what the autumn term will look like, and not to plan for various eventualities. That's exactly what they are doing now. My university has apparently modelled eleven different possible scenarios. They can guess how the pandemic might proceed globally (this is different from schools as there is only a local dimension to their planning) and plan business continuity according to different models, but they can't say for sure right now what will happen.
With students in the lower risk age group opening campuses is probably less contentious than say primary schools.
I'm not sure about this. Students are higher risk than primary school pupils, plus there are significantly more staff working on campuses (several thousand as opposed to, say, a hundred). And not all students fall within the 18-21 age range. Academics also often can't cover each others' teaching if we get ill, because much of it is very specialised. That risks teaching stopping if staff get sick. Which is one of the arguments for online teaching, which is at least pretty much guaranteed to proceed.
Personally, I will want PPE if I'm to be in a lecture theatre being coughed at by hundreds of students and having to use equipment that other people have touched that day. I wonder how great an experience it will be being taught by someone wearing a mask. That would seriously affect the teaching dynamic, I would think.