Having a house full of Echo’s is useful, especially the multi-room audio , but 
having the kids song choices populate my playlist can get annoying at time, so news that the Echo’s will personalise actions based on id’ing you based on your own voice is welcome.
It looks like it must be region specific at the moment as although I have the latest apps, I don’t have the menu option to set up.
more details at https://www.digitaltrends.com/home/amazon-alexa-2/amp/