The new smart home standard Matter, which is backed by Apple, Amazon and Google, will allow control of TV functions like on/off and volume and also include universal TV casting, according to The Verge.

Matter TV control & casting
Matter (formerly CHIP) was announced in 2019 as a new royalty-free smart home standard that aims to achieve interoperability across ecosystems, products, and brands. Amazon, Apple, Google, IKEA, and Samsung have already committed.

Matter will control core TV functions and a new universal casting system will apparently also let you share content from a phone, tablet or PC onto the TV screen, according to The Verge.
Matter TV, as we’ll call it for wont of an official name, will allow control of a television’s core functions — volume up / down, changing the channel, controlling inputs and outputs, and switching between HDMI ports. "But importantly, you can also do casting," Chris DeCenzo, Principal Software Development Engineer at Amazon Lab126, told The Verge.

 Matter will also control lights, cameras and other IoT devices

Initiative led by Amazon
The casting initiative is led by Amazon, which does not currently have a strong alternative to Apple's AirPlay 2 and Google's Chromecast. 

Companies like Apple, Google, Samsung are not required to adopt Matter's TV specification but if they do, they will have to adopt it fully including TV control and casting, the report said.

Apple did not comment on its plans but Google said that "Google Assistant will support Matter (eg. on/off, play/pause, app launch etc.) at parity with our current Works With Assistant offering" but added Chromecast will remain its preferred method for sharing media to Chromecast, speakers, and TVs.

However, it sounds like casting could still work on other platforms as it is an app-to-app protocol that app developers can implement at will.

At launch in 2022, Matter will rely on Ethernet, WiFi, and Thread to communicate between devices.
When Matter arrives in 2022, the Matter TV specification will use app-to-app communication, at least until the TVs and streaming video players become Matter enabled. The spec supports casting from a Matter client (e.g., a remote, a smart speaker, or a phone app) to an app running on a Matter-enabled TV or video player device, explains DeCenzo. It also supports URL-based casting, which means a Matter client can cast to a TV even when there’s no app for that client, if the TV supports Dynamic Adaptive Streaming (DASH, an international standard for streaming) or HLS DRM streams (HLS is a video streaming protocol developed by Apple and widely supported across Android devices and browsers).
- Source: The Verge