I knew there was at least another state that did it, but couldn't think of it. Also, the state I was thinking was Oklahoma. Who does do it for their 6A class.South Carolina did this for a number of years as well. Back when we had a four class system, 4A had two separate playoffs, 2A and 1A did as well. I think only 3A was a single state champion. In the case of South Carolina, the separation come playoff time was based on enrollment. All 32 playoff qualifiers in 4A would be ranked according to enrollment and then split into 4A-1 and 4A-2. Rarely, but it did leave the door open for the two best teams to be pitted in the same bracket and left the other bracket with maybe not the most qualified state champion.
Since this has warped into a discussion of just everyone making the playoffs regardless of split, Indiana's is setup in a similar manner. If there's too many teams in the six classes either they'd need to add another class or restrict participation. However, they're pretty happy with their tournament. it's an open blind-seed tournament. You have the regular season and then you have the tournament. it's not seen as a playoff the way most states do it. It's just another part of your season. Everyone plays at least one game, you can play anyone home or away in that first round. And home field isn't a thing.
Another oddball is Illinois.
In Illinois, not everyone makes the playoffs, but the classes (8 of them) aren't decided until the regular season is over. Any team with 6 wins is automatically in the playoffs. The league schedules vary throughout the state. If you win six games, regardless of against who, you qualify for the playoffs. I believe there's a provision for letting in 5win teams to fill in the roster). The 1/8th largest schools become 8A, next 1/8th is 7A, etc. So, your class isn't set until after the season. So, no complaining about being the small team in a class or large team, because you don't even know until the roster of participants is set to see where the dividing lines are placed.