What Does This Mean On Messenger?

[Scarlett]

If you have sent a message to somebody who is not your friend, and five days later you get this message: "You can now message and call each other And see info such as active status and when you have read messages"

any idea what this means?

[Auntypoll]

It means the person you sent the message to has opened your message and read it, therefore adding you to their contact list. 

[Scarlett]

Thanks Aunty!