What the 2020 Mulan got wrong: Yes, in the original ballad Mulan did decline a prestigous job offer and went back home, but No, the ballad wasn't glorifing her female role/ "devotion to family" over a career of her own.
In Chinese culture one of the highest-regarded virtue is one's indifference to fame, wealth and power: the ballad was celebrating Mulan, who reject the emperor's offer, as a truly free spirit, uninterested in "success" as defined in a man's world.