I think there has to be a balance between the two extremes. On one hand part of the fun is that flirty ambiguous stage. On the other, nothing is more aggravating than having someone play games with you.
In regards to the OP... I've had two extremes. A few times learning a guy liked me did make them seem more attractive... But these were men I already found attractive. Other times if I learned this and I had zero interest, then it caused me to avoid them.