This list is managed by Microsoft engineers and currently contains 1,156 entries.
Big names on the list include the likes of YouTube, Instagram, Twitter, Yahoo Mail, StackOverflow, StackExchange, VK, ESPN, Chase, Hotstar, Moneygram, eharmony, and GoDaddy, just to name a few.
This means that starting with next month, most IE users won't be able to load these sites inside Internet Explorer, and every time they will try, the site will be opened inside a new Edge window. [see a video here]
Inside IE, the DLL will load the following page, explaining why the site couldn't be loaded with Internet Explorer anymore.
Since this is a pretty intrusive new behavior, Microsoft is taking care to provide group policies to enterprise customers so they can disable the forced IE-to-Edge behavior, or at least control some aspects of its behavior.
Obviously, this new action is only available on systems where both Edge and IE are installed. System administrators managing older workstations where only IE is installed don't have to worry about this forced redirection to Edge.