I was developing an app for Android TV which required a push notification support and my basic question was does Android TV support Push Notification? and the answer is Yes, Android TV runs Android inside and hence it supports push notifications, however below are some caveats

1. You may not be able to display those notifications as it appears on the phones and tablets.
2. There are no notification inboxes, so only possibility is to show them as Recommendations which is not really ideal.

I developed a sample App in Kotlin and used FCM as my push mechanism and sent some of the pushes and my TV emulator was able to receive it.