I think the biggest reason the UW went with Fickell over JL is because they are moving away from the Wisconsin way or at least trying something different.
I believe Allen, Mertz, Herbig, Dike and others will all be gone either through the transfer portal or declaring for the draft (Herbig). That is a lot of holes to fill. If JL is not back as the DC then there could be a exodus of players on the defensive and probably on the offensive side.
I think the Badgers are going to be the worst team in the B10 in 2023 and they will be lucky to win 4 games. Even with all of the players coming back this team is probably still just a 5 or 6 win team at best.