Warning: this reply may contain political content - perhaps better suited for off topic bd...
Please excuse my ignorance. I am an older alum who has been living in Las Vegas and the western US for 30 years. When did the basketball arena first get called "The Barn"? I believe it was always just called Williams Arena back in my days and before.
"The Barn"
Good question. I remember it mostly as Williams Arena as well. I don't believe the name has ever officially been changed to "The Barn". However, during the Mussleman era the crowds of 18,000 plus prompted some occasional visits from the fire marshalls. I believe it was most commonly referred to as Williams Arena however, the phrase 'barnburner' became a little more prevalent and the term 'barn' began to be used more often.
The election of Ronald Reagan in 1980 prompted a plebiscatary love affair with everything private and the denigration of anything to do with the government e.g. schools, roads, public safety, air traffic control, regulation etc. 'Privatization' and a condemnation of everything 'governmental' was now in vogue. Money makers now saw a way to make a private profit off of anything - amateur sports included. In LA 1984 Peter Uberroth privatized, corporatized and profitized the Olympics for the first time. This was the beginning of the attempt to make a profit on everything connected with 'amateur' sports. Marketing was KING and it has promoted a long line of marketing gurus that has now culminated in our most recent local 'marketeer' - js strings. This has also resulted in a visual assault in 'The Barn' of wall-to-wall signage accompanied with nearly non-stop audio commercials when the ball is not in play including pushing TCF Credit Card debt for all students .
However, when Clem took over the reigns from Dutcher the place was still often referred to as Willam Arena. The term 'Barn' was definitely there but was not being marketed to its fullest potential. In the early 90's there was some talk of raising the barn but there was enough opposition (mounted by Sid & others IIRC) to keep it from the clutches of the Fire Marshalls and the capacity was reduced down to 14,000 during a series of renovations. In 1997 according to GopherSports .com "Barn Lofts" above the second deck were installed as part of the last phase of renovation of Williams Arena. That is when I think the term "The Barn" became cemented in the marketing jargon of Golden Gopher Basketball.
None of this is guaranteed and would likely not pass the muster of Wikipedia.
Did Jules Perlt ever say, "This is Golden Gopher Basketball"?