Since this appears to be strictly a notification for now, I expect Hackintosh users will see the message once, choose "Don't Send", and never see it again. According to the article, once you've made your choice, that choice is remembered between reboots.

Long term, I could potentially see this being modified to pop up every time on startup, as a "We know what you're doing, and we don't like it" signal to the Hackintosh users out there. However, that seems like kind of a dick move for such a small (and passionate) fraction of your market.

Tried to use iMessage on a hackintosh recently. Don’t do this, and don’t let anyone you know do it. Watching your services get switched off in a cascade is rather awful.

Did you generate a valid serial number / model combo first?

It wasn’t my machine but I think that had been done. It thought it was a nice new iMac.