https://www.steelers.com/news/asked-and-answered-dec-8-x9062
DAVID BOGNAR FROM GERMANTOWN, WI: How and when did the Immaculate Reception get its name, and who came up with it?
ANSWER: There are many who claim to have been in attendance at Three Rivers Stadium on Dec. 23, 1972, who weren't, but Myron Cope was there and had a hand in naming what now is recognized as the "Greatest Play in NFL History." Cope was the color analyst and Jack Fleming handled the play-by-play for the radio broadcast on WTAE-AM of the Divisional Round Game between the Steelers and the Raiders, and Cope wrote about how the play got its name in his book, "Double Yoi!"
Wrote Cope, "After the game, I dined with my wife, then drove to Pittsburgh's WTAE-TV studios to deliver a commentary on the game for the 11 o'clock news. Meanwhile, a Steelers fan in his late 20s, Michael Ord, was celebrating Franco's catch at a downtown bar fittingly named The Interlude. Boisterous fans toasted the victory. Ord climbed upon a chair and with a spoon tapped his glass for attention. 'This day,' he proclaimed, 'will forever be known as the Feast of the Immaculate Reception!'
"Then, to a friend, Sharon Levosky, Ord suggested, 'Call Myron Cope.' When my phone rang in the newsroom, I listened to Sharon's suggestion and said, 'That's fantastic. Let me give it some thought.' The Immaculate Reception? Tasteless? I pondered the matter for 15 seconds and cried out, 'Whoopee!' Having conferred upon Franco's touchdown its name for 11 o'clock news viewers to embrace, I accept neither credit nor, should you hold the moniker to be impious, blame."