Hi, eddie, I think there's a misunderstanding. When you say the "YouTube app" on your Fire, are you referring to what appears as an app which actually reads "youtube.com" if so, that is not really the YouTube app. I went to my Fire soon after your post and saw the same youtube.com Fire app, but not the true YouTube app.
Amazon's solution to no longer having the real YouTube app was for Amazon to create its own Fire TV app that when launched takes you to YouTube.com website via Amazon's Silk browser or the Firefox browser. The display and experience of the work around youtube.com app is very, very similar to the true YouTube app. In fact, I find it functions just as well as the true YouTube app did. this confusion also explains why there is still no YouTube app on Echo Show products because Amazon and Google have not kissed and made up, yet.
Please be aware that there are other third-party apps that also connect to youtube.com with various names like kids for YouTube as opposed to the official YouTube for kids, or videos for YouTube etc with the same bright red color of the official YouTube app., but none of those are the official YouTube app. instead they are apps from third-party developers Perhaps you saw or downloaded one of those. As far as I know Amazon still does not offer the true official YouTube app from Google's YouTube.
Unless I missed something I can't recall nor find any announcement that Amazon and Google have made up, so Amazon cannot offer the true YouTube app. Am I wrong or was this just confusion of similar looking apps that are not officially from YouTube?