it's to maximize the string break angle and also to help the string to clear the edge of the Mustang bridge , low E and high E strings often catch on the edge of the bridge if it's not totally inclined towards the tremolo , as the saddles are not height adjustable and are smaller for the E strings .
Raising the bridge also helps , it puts more downard pressure on it. raising the bridge lets the tiny pointy screws come out of the bridge , I find it rocks better back and forth with these tiny points fully exposed .
it's the downard pressure which is the most important for stability , which is why heavier strings work so well to fix the Jag/JM 's "problems" : putting flatwounds 11's on my ClassicVibe and 40th anniversary made them totally stable tuning wise, with heavy use of the vibrato.
BTW I really love this metallic brown color on the new Affinity , is there some gold flakes in it ?