Sadly I can see the Android TV app going down the Roku app path - unsupported, then deleted from the app store. 

Thank you @Rick P. for the info. 
 

So then what would even be the point of keeping my subscription at that point? Every other music streaming service has a functioning TV app except for Deezer. I love to listen to music on my TV, so that'd be such a stupid decision on their part. I'd definitely unsubscribe at that point. 

I completely understand since we use the app on our TV to listen to music all the time. Fortunately for us our Sony TV uses Google TV, which is at least partially supported. As a long-time Deezer user I thought it important to temper expectations here.  I'm not saying Tizen won't eventually be properly supported - as a user, what do I know. What I am saying is that Deezer has a poor track record of expanding or even maintaining hardware support, so don't hang onto your subscription for a couple months in hope of it being improved soon. 

Since this is important to you, if the existing apps dont meet your needs I suggest canceling your subscription, using something else and perhaps keeping the occasional eye on this forum or Deezers website to see if support is added, then you can consider whether you want to return to the service. Fyi, unless you're really into music videos I wouldn't recommend Tidal since their TV apps know you're using a TV and show music videos instead, and i haven'tfound a setting to turn this off. I guess this isn't a bad thing if you're into pop music but if you've got eclectic tastes or listen to a lot of indie stuff where the artist didnt make a music video you might not like the playlists Tidal suggests for you.