If you can't beat them (or stick with them) at the beginning of the season, you probably won't in the playoffs. Any yes, I would expect the Bison to be in the playoffs.
Do you want to make the playoffs, or win in the playoffs? I'd prefer to win. Beating UND would be huge for any team in the FCS, why would we be any different. And yes, there is a rivalry factor. And recruiting implications. And it would be a driving force more more following and fan involvement.
Not sure which part of that wouldn't be critical in building up the program.