Twitch can forward the stream as is without transcoding it. That's what transcoding not being guaranteed means. It will be a worse experience for viewers but it

Twitch can forward the stream as is without transcoding it. That's what transcoding not being guaranteed means. It will be a worse experience for viewers but it can work. Few years ago they even announced working with OBS on feature where streamers themselves can transcode and send multiple streams further reducing need for twitch to spend their compute resources on unprofitable streamers.