As Catty said, its just bavarian and Bayern does it every year, which is a nice tradition. I like it, but maybe because I was born in Munich
Normally even people from other regions or cities visiting the Oktoberfest dress up like that aswell, to join the fun. But I am not even sure other teams will go there, tbh.
As for the friendly tomorrow, I will check, but I guess if it is shown, it is probably Sport1 or so in Germany... if I find anything I will post it here!