Seems like the larger problem is not Madison High School. If the name Madison is somehow deemed Racist, then the city of Madison, Wisconsin will presumably desire a more woke name also.
I fail to see how erasing history somehow makes any country better.
There are twenty seven cities and towns in the US named Madison:
https://geotargit.com/called.php?qcity=Madison
There are schools, streets, lots of people(!)....this cancel culture oscillates between the frightening and the absurd.
The thing about changing names is that when sanity returns they can be changed back like Leningrad back to St. Petersburg. :)