Have American universities cut back on H1-B visa sponsorship of new international faculty and F-1 student visa sponsorship for PhD students? Concerning industry, I've read that Google and Amazon have cut back significantly on its H1-B visa sponsorship of new candidates (though it's unclear what the renewal rate is for currently sponsored employees.) 

Is the same sort of thing happening in academia?  Are American universities cutting back its H1-B sponsorship of new, international faculty candidates and student visa programs for its international PhD applicants?
The current ban was stopped by court, 
we are waiting if supreme  court of USA will take complaint from Trump administration but that will likely not happen because of the composition of a court. 
Regarding American universities, occupations that are related to academia (post-doctoral fellow, research fellow, etc.). You can check referenced link and put desired profession name in search menu and compare rates of awarding H1B by the universities.
Conclusion is honestly that university never awarded so much H1B in a first place, and it is a noticeable trend of declining H1B sponsored by academic institutions ( institutes, universities, hospitals... etc..)
website myvisajobs.com give you opportunity to search and compare different occupation and employees.