The new Twitch App is available on Samsung TVs without Gaming Hub. I have an 2021 Device and was able to find the new Twitch App using the search (not browsing in the app store) and it is working great.

There used to be a third-party Twitch app for Tizen TVs, but Twitch shut it down in 2019 due to unauthorized use of the Twitch name and logo. And apparently Twitch didn't bother to provide an official app back then, they just asked Samsung to remove the existing one. There was a request on this forum for an official Tizen app with over 2000 upvotes, but they closed it just recently. Why did they close it? Twitch has announced support for the Samsung Gaming Hub, which will only run on Samsung TVs from 2022. Apparently older devices will never get a proper Twitch app. But they used to have one! Good job Twitch, good job.

Tizen app would be awesome!

How to run pre-paid video streaming in apk?