The Microsoft Windows team mentioned on August 15, 2016 that they were working on releasing an updated version of the Microsoft Update Catalog which would eliminate the need for ActiveX requirements in order for the site to work in any browser.
The Microsoft Update Catalog website is being updated to remove the ActiveX requirement so it can work with any browser. Currently, Microsoft Update Catalog still requires that you use Internet Explorer. We are working to remove the ActiveX control requirement, and expect to launch the updated site soon.
Good news! As of yesterday, the site has been updated and you can now access the Microsoft Update Catalog site using any browser including Edge, Google Chrome, and others with the following URL: http://www.catalog.update.microsoft.com. Here’s the blog post by Michael Niehaus with the announcement.