PBF will not face Pac. Maybe at ~154, but no way anywhere near his natural weight.
To be honest I don't think Pac has any interest in facing floyd. Sadly, Arum is right about a couple things.. Floyd fights are just not entertaining. Pac can prove so much more than Floyd. There are actualy "threats" in the LWW adn WW limit.

Everyone is stuck looking at one thing... Floyd is undefeated. That, by no means makes him the best fighter in the world. Shane Mosley, Cotto, Berto, would all whoop that butt.