Did you ever read the Case Book before?
Again, it's always been in the Case Book, under the same article. But the ruling is new.
Old Play.
9.1.1 SITUATION:
A1, at the free throw line to attempt a free throw (a) muffs the pass from the official and it rolls forward; or (b) accidentally drops the ball before the throwing motion is started.
RULING: In (a) and (b) the official should sound the whistle to prevent any violations and then start the free throw procedure again.
BTW, I've never had it happen that I can recall.