https://www.techradar.com/news/reddit-redesign-rolls-out-to-a-random-group-of-hopefully-happy-users

Big changes are happening to Reddit, with its mods announcing a redesign that's involved a "massive undertaking" has started to rollout to a handful of users. 

Those getting the new desktop redesign have been chosen at random and they can revert back to the old design at any time. Reddit is hoping that won't happen, however, as the changes it has made are meant to speed up the site and to "make Reddit more welcoming".