What "Applicant Confidential Data Form" has to do with tenure-track positions? The data collected using "Applicant Confidential Data Form" will be used by US-based universities to monitor University’s Affirmative Action/Equal Employment Opportunity Programs as required by the US government. 

I have seen that in (some) cases, faculty job applicant seeking academic job in US-based universities are asked to submit this form after they successfully submitted their initial application. The point is that, typically there is no instruction in "call for faculty member note" to fill this form and submit along with application. But the faculty search committee asks after while.

So it raises a question:

Do the faculty search committee sends this form to ALL the applicants or particular applicants who are allegedly suitable for the job. Is receiving this notification from the committee can be considered a positive sign in recruitment process?
I've received this form from hundreds of employers that later rejected me. I think schools that use it will send it to every applicant. So it doesn't mean anything except that your application was received.

I believe the reason for it being a separate form, rather than part of the application, is that it's meant to be for statistical purposes only, and should not affect the hiring procedure. The best way to achieve this is to ensure that the hiring committee never sees it. So they send a separate form, to be returned to a separate office within the institution, which holds it confidential.