Yup one college we are looking at states openly that they become need-aware when considering people on the WL.
Re: “students who they think will take the offers!” haha yes for sure, they are super yield focused at that point obviously 
and at least one school I know of asks you outright if you’ll accept if granted an acceptance before actually accepting you.
But even then, let’s say that full-pay is 1/2 the WL. Do they look beyond yield to other aspects?