History would suggest no benefit to a single regular-season loss
Ten unbeaten regular seasons:
UCONN finished the regular season unbeaten in 1995, 1997, 2002, 2003, 2009, 2010, 2014, 2016, 2017, and 2018, winning the NC in seven of those ten years (Losing in 1997 after a major injury, and also the past two years, taking a BE semifinal loss to Villanova in 2003 but prevailing in the NCAAs)
Four single-loss regular seasons:
UCONN took a "Fortuitous" regular season loss four times: to Tennessee(by 1 point on a buzzer-beater IIRC) in the 2000 season, to Rutgers in 2008, to Stanford in 2010-2011, and to Stanford again in 2015, winning the NC in 2000 and 2015, losing in 2008 and 2011, succeeding twice in four instances. You can argue the 2003 loss to Villanova into whatever category you want, but the Rutgers loss in 2008 and the Stanford loss in 2010-2011 were ultimately no help. I remember the relief felt in December 2010 when Stanford ended the 90-game winning streak, but there would still be no NC.