Some quick sleuthing.
I noticed the library website has this announcement: "
Nobelbiblioteket har, med anledning av coronavirusets spridning, stängt på obestämd tid. Inga nya boklån kan göras och redan utlånade böcker behöver inte återlämnas förrän vi har öppnat igen."
The library is closed because of COVID-19. It says no new books can be loaned out but that books currently on-loan don't need to be returned until the library reopens. Referencing Waybackmachine, it appears this notice popped-up around May 20th (
https://web.archive.org/web/20200520083313/http://www.nobelbiblioteket.se/).
From this I'd like to raise two points.
1. This may only affect the general public, not the Academy Members.
2. If books on-loan to the general public can't be returned, does the website show old due-dates or updated ones?
If it's the former (old dates), it's safe to assume on-loan dates in or past July are from Academy Members, as the public's 30-day loan period from May 20th wouldn't go into July.
Some authors I saw with July dates are Annie Ernaux, Can Xue, and László Krasznahorkai.
(Also glad everyone is safe and healthy despite the virus!)