It's more nuanced. Munich has municipal schools and at least on administration side it can do what they want there. However curriculum is made on state level, t

It's more nuanced. Munich has municipal schools and at least on administration side it can do what they want there. However curriculum is made on state level, thus if the curriculum depends on Microsoft software (explicit about Excel etc.?) They would have to comply. Also some state funding budgets, i.e. for getting a few machines, might be bound to "default configurations" thus for going Linux the city might have to pay out of its own budget ...