How do I disable "rich links" in Messages in Sierra? I don't want every link I send through iMessage to be accessed and embedded inline. I can't find a preference setting or defaults key to turn this off.

In this example image, I would want the YouTube link to be sent as a bare link, not a movie + screenshot:
That can't be disabled, it's part of iMessages.

https://support.apple.com/en-us/HT206894