I mean that's fine, but you are the registered owner 》renter of that domain, so you are linked to it in a database somewhere, even if your info is behind whoisguard-style obfuscation. Even if unlikely, should a dataset get exposed or the service stop functioning as intended, you're linked. No real worry for singing up for future junk-mail, but risks escalate when employment is at stake.

That’s fine. If they can’t deal with my real opinion it’s better to end that working relationship anyways.