Thanks! It is a bit curious that this warning was left out of the system to seemingly focus on positivity, and then the next addition was trust flags that are purely negative.
I can see not wanting to label every outside link with a warning as that would seemingly be harmful to business here. A better compromise to my previous idea would be to only make outside links red that are disguised using the url command. That way users could post outside links without them being red so long as the link was displayed naturally. If they try to disguise the link's true destination by using the url command, it would display as red, warning the user that the actual destination is not being displayed and needs to be checked.
Example:
Check out this cool new way to donate: Donate to Bitcointalk (link would be red)
Check out this cool new way to donate: https://bitcointalk.org/donate.html (link is green)
Check out this cool website that I like: https://www.wandera.com/signs-youve-been-phished/ (link is normal)