Currently, it can be set so that when someone presses the doorbell button, the live video are shown on multiple Echo Shows (so long as you select them under device settings in Alexa).
There is a toggle for motion announcement, but it’s announce only on the Echo Shows. If you are forced to create a routine to show the live video, only one Echo device can be selected.
It would be helpful for Amazon to integrate the live video for motion as it did for doorbell button press. Thanks.