Seems bizarre to me. Maybe I don’t pay that close attention
This list includes
only the P6 12 seeds that won at least one game, dating to 1985 (beginning of 64-team format) … there probably are more, don’t have time right now to check fully. (Some were auto-bid, some at-large)
… I also noted some that went beyond R32, but it's all off the top of my head, might have overlooked some older ones.
2021: Oregon State (reached Elite 8)
2019: Oregon (reached Sweet 16)
2013: Oregon (reached Sweet 16)
2013: Ole Miss
2013: California
2009: Wisconsin
2008: Villanova (reached Sweet 16)
2006: Texas A&M
2002: Missouri (reached Elite 8)
1998: Florida State
1996: Arkansas
1985: Kentucky