+1 for this.
I've been researching options given this feature gap, and am about to switch from my Roku Ultra to an Nvidia Shield so I can receive Home Assistant notifications on my TV. Even though it's old, there aren't a lot of non-Amazon, non-Google options for this.
You'd think Roku would appreciate the network effects of leveraging standards like Matter. Walled gardens only work when you have a material market share.