Gus Malzahn's 100th game as Auburn's HC was also Auburn's 100th win in the post Senator-Tuberville era as Auburn's coach.

This took 11.5 years and is pretty much exactly on par with the previous 11.5 years of Auburn football (10 under Tubbs and then previous 1.5).

Auburn, 1997-2008:
98 wins & 51 losses, 3 10-win seasons, 9 bowl games, 3 SEC CG appearences (1 win), 1 should-be NC
Auburn 2009-2019 (1 year fewer but extra game/season):
95 wins & 50 losses, 3 10-win seasons, 10 bowl games, 3 SEC CG appearences (2 wins), 1 NC (&1 runner up)

It's amazing how Auburn is in some ways the most unpredictable team but also in some ways the most consistent over a long period. It's hard to find any random group of 10+ seasons in which Auburn's average isn't fairly consistent. Half in order and half in chaos.

All coaches run their course and have a built in shelf life of roughly 10 years in the modern era. It's likely Gus' shelf life is near the end. The one good thing he has going for him is he hadn't "lost" a team yet, the way Tubbs, Bowden, and Chiz did.

But unless you get a legit home run hire who pans out, it'll be new boss meet the old boss kind of thing.