<p>“they can probably tell by your last name anyways”</p>
<p>Excuse me?</p>
<p>OP, if you declined than indicate it on your application, then your application will not be treated the same as if you had. Now, it may influence the decision of whoever reads your recommendations if it gets to that point, but otherwise you cannot expect an adcom to assume information that you had the opportunity to indicate yourself.</p>