Being undefeated does help with the polls, but the CFB ranking system is a bit more than that..
"Unlike other polls, the College Football Playoff rankings come out only until well into the season. And unlike other polls, it's the only one that really matters, as it's for the 12-team playoff. For a decade, the CFP was only a four-team playoff. Starting with the 2024 season, it moved up to 12 teams. The CFP Selection Committee ranks its own top 25, using factors like strength of schedule, results, championships won, common opponents and more."
I'm sure the 2 polls will influence these rankings, but I doubt that Liberty gets back in it this year if there is a 2 loss team from the MW, maybe even a 3 loss team. The fact that they got curbstomped probably hurt them from repeating.
Not to say that a MW team in the same situation wouldn't also be curbstomped, but it seems like top MW teams have faired a little better than that when they have played top schools in the past.