Hi Ruben,
Since these are "manual" messages, a Google employee had to personally review the account and decide to send the message. It is likely something about the site flagged Google, prompting them to manually review the site. We don't really have a way of knowing if what they address in the message is what flagged that site, but it is likely.
If Google thinks what this site did violated the guidelines, that means any site, including your own, that is in violation of that guideline has the potential to receive the same message.
It is likely that yours is "in the mail." You could receive it a week from now or ten months from now.
I would recommend cleaning up or "no following" the link. You might consider waiting until the other site has submitted their reconsideration request to find out if your actions to remove the link were acceptable.
