[BillyMac]

Looking for citations, I've searched the NFHS rulebook, the NFHS casebook, Forum Annual Interpretation Archives, and Forum Search and came out with nothing.

Finally, in desperation, I tried a search on the Google and came up with these three Forum posts:

BillyMac October 2008
Resumption Of Play Reminder ...
Just a reminder: A few years ago the Resumption of Play procedure, which used to only be used after time outs and intermissions, was changed so that it can also be used during any throwin.

BillyMac November 2008
Sometimes A Technical Foul ...
Remember, the Resumption of Play procedure is only used for a free throw after a timeout, or intermission. If the free throw is not after a timeout, or intermission, and the team delays, it's a technical foul.
The Resumption of Play procedure can be used for any throwin, not just a throwin after a timeout, or intermission.

Nevadaref November 2008
9.2.9 SITUATION: Following a violation, the official has properly signaled and
awarded a throw-in to Team A at a designated spot. No Team A player comes to
the spot even though the official has allowed ample time for them to respond. The
official then places the ball on the floor and begins the five-second count. (a) Both
A1 and A2 step out of bounds and A1 picks up the ball; or (b) both A1 and A2
step out of bounds and A1 picks up the ball and hands it to A2. RULING: In (a),
A2 must immediately return inbounds. In (b), it is a throw-in violation when A1
hands the ball to A2. (9-2-12)

What was this "change" I was talking about?

I wish that I had done a better job at posting citations (evidence).