It should not IMO (and almost certainly will not) be made illegal. I’ve worked with or near maybe 1000 people in my almost 30 year career. Many of them I’d love to work with again or to refer to friends’ companies. Others, I have the opposite opinion.

It seems beyond unreasonable that I couldn’t make use of that information in choosing who I will work with professionally.

To me, it’s a clear-cut freedom of association (and/or a freedom of speech) right.