No, I guess he chose TR consciously because it is so long and so ambitious and so complicated, compared to other Dire Straits songs. He had done all this brain work to do it properly and then, I think in an elevator it was, listens to a 2 or 3 minute Buddy Holly song and sees the impact that this song had on himself - and he recognized that he was on the wrong way with his own music, related to his own roots. Keep in mind that after Love Over Gold, he made that Rock'n Roll EP, simple, easy, great nevertheless.
Of course Telegraph Road is a master piece, I fully agree with that, but I guess it just broke out of him like the whole album did in some sort of creative explosion or eruption. Many songs on his recent solo albums have chosen to go the other path, the Buddy way, Who's Your Baby now, True Love Will Never Fade, and so on.
LE