Does advertising a minimum required credit score or credit score range trigger additional disclosures on a consumer real estate ad?

That alone - no.

How many prospect real estate buyers know their current credit score? Isn't there a better way to get prospective real estate buyers to 'pre-qualify' themselves?

WW - there are many credit scores. Even if one was pulled from a major vendor, the score the bank uses can be very different. (A general credit score is usually offered by the major CRA's. Your bank may be using a mortgage credit score [heavier emphasis on mortgage loans] or a tri-merge.

There could be a reputational/regulatory risk if applicant gets their score e.g. from Equafax which says 650, and the bank pulls one and it's lower and the loan is denied.