While that is factually correct, the reference in the name of the autonomous community isn't to the city or the province, but to the Leon region [0], which expands to the south of the province, following old demarcations, and older language areas and finally the borders of the Kingdom of Leon [1].

[0] https://en.wikipedia.org/wiki/Le%C3%B3n_(historical_region) [1] https://en.wikipedia.org/wiki/Kingdom_of_Le%C3%B3n