Bart, so I tested it. This only pops up when you aren't logged in. So they're still lying to you by saying "please use the app" instead of "please log in". But even then, you can still view that same damn "unreviewed" subreddit anonymously if you open old.reddit.com, so the account requirement is, of course, entirely artificial ¯\_(ツ)_/¯

YouTube is at least 100% consistent about it.