Microsoft is doing an A/B testing of a new functionality in the latest Windows 10 Insider Preview that reminds users of Microsoft Edge whenever they try to install another browser such as Google Chrome or Mozilla Firefox. Microsoft, however, said that this is limited only to the Insider Preview Builds for feedback and will not appear in the final shipping release.
https://www.notebookcheck.net/Latest-Windows-10-Insider-Preview-Build-tries-to-dissuade-users-from-installing-Chrome-or-Firefox.331522.0.html