The rule change is ridiculous and Manning, the Colts and everyone else in the league have the right to be upset.
By making the QB to look to the sideline ref, who will signal the QB when it's ok to snap the ball, you're slowing the game down at the most critical time of the game. During a "hurry-up offense", the whole point is to catch defenses off guard, to snap a ball before a close call is reviewed or to beat the expiring clock.
Add this to another laundry list of things for a QB to do: take in the play call from the sideline, relay that call to teammates, audible at the line, direct teammates into position, instruct the O-line of any audible or opposing defensive switch, mind the game clock, all at a quicker pace than the opposing defense which is the whole point of a "hurry up" scheme. Now you're asking them to WAIT for the ref to get into position before you snap the ball? And now it'll take the ref longer to get into that position than in year's past?!
Ridiculous. I don't care what you're rooting interest. This needs to be corrected. You're messing with the game.