The company says services like Plex, Pluto TV, Sling TV, Starz, and ZDF will introduce support later this year.
I always had the impression that plex was really slow when it comes to implementing new features. I'm definitely looking forward to a chromecast alternative though. Being locked into googles DNS gives me problems due to it prohibiting streaming from my local server via hostname.
I really hope it will be implemented in Jellyfin as well since I can't get my installation to work with Chromecast at all (most likely again due to the DNS issue)