Negative (prior poster). It is not the team that wins the higher seeded regional. Assuming both teams bid, it is the higher seeded team ... except only the national seeds are seeded in softball (unlike baseball). Thus, if neither team is seeded (as would be the case with Louisiana and Auburn), the teams are evaluated as if they were being seeded by the selection committee. The team evaluated to be the strongest is declared the host for the super regional round.
In this situation, I do think that Auburn will be evaluated to be the higher seed and thus the host.
I was serious when I said I did not think the Cajuns would be close to being a national seed and host team. I do not think they were one of the Top 20 teams.
Brian