Penn fans had a similar discussion in 2002 when a great Penn team beat Georgia Tech, Villanova, Temple, Iowa State, and St. Joe's. I think Penn finished with an RPI of around 35th, but had to win a playoff game vs. Yale to get the league's NCAA bid. If Penn had lost that game there was some question as to whether they would receive the league's first at-large bid.
This year Bucknell is 38th in the RPI with wins over Syracuse, Depaul, and St. Joe's. It will be tough to keep that RPI up with only three regular season games left against teams with winning records (plus the Bracket Buster), but assuming Bucknell wins out until the PL tourney championship game, let's say the RPI remains about the same.
Anyone think Bucknell has a shot at an at-large if it loses that game? I think they'd pretty much have to go 14-0 in the league and get to the tournament championship game to have a realistic chance.