Is it possible to target Apple TV and Android TV with a CapacitorJS app?
No, it’s not possible because AppleTV has prohibited to use the WKWebView inside AppleTV apps.
There are ways of still using the WKWebView, but will most likely lead to app rejections and a bad user experience since the component is not created with Apple TV in mind.
This does not at all answer the quesiton, but maybe you can try using the app through the TV browser, if you host it as a website too. It worked like a charm for me.
Unfortunately, directly targeting Apple TV with a CapacitorJS app is not possible at this time. Apple’s App Store guidelines currently prohibit the use of WKWebView, which is the core component that Capacitor relies on, within Apple TV applications.
With this browser I do not mean the Apple TV in-built browser, but instead your tv’s OS-browser