They should be very, very slightly less visible (they will have slightly fewer resources to use due to expending some on keeping their parent species happy, and FAI is more likely to have a utility function that intentionally keeps itself invisible to intelligent life than UFAI, even though that probability is still very small), but this difference is negligible. Their apparent absence is not significantly more remarkable, in comparison to the total remarkability of the absence of any form of highly intelligent extra-terrestrial life.