Huge bummer that they're all 5+ years old. We've been moving to libreelec with Disney+, Jellycon, Netflix, Youtube, and amazon prime plugins. It's not the same, but it's workable. If Amazon keeps MatterCast open and open source implementations get made, that's where I'm focusing my attention. A raspberry pi with libreelec that can be a casting target feels, to me, like the holy grail: