well

This is ancient Chinese culture. The issue is that in many Asian cultures they believed that is someone was harmed it was a form of them being paid back for an evil they committed in a past life. You also have the whole 3 generations will pay for the crimes a family member commits. This in fact still goes on in North Korea and in many communist nations as well. So it would likely have been the court that holds a lot of the power that would have pushed for him having to abandon the concubine and thus in turn their son. Keep in mind it was the lords the officials in the court that controlled the land by keeping it maintained. As such these lords of a section of the land hand the power over the people and could manipulate the citizens in their area. If a corrupt lord started to do wrong and corrupt the citizens in the area they could in turn lead a revolt against the Emperor. The Emperor had to have solid evidence to prove the lord was corrupt to get them removed. This is why many lords in the courts would do all they could to get their daughters into the harem as either a concubine or an official wife. These lords would use their daughters in the harem to sway the Emperor. The concubines would do all they could to take each other down so that their family outside could rise in power. The power the lord's held with the concubines inside was a form of blackmail they used against the Emperor. Each family was partial towards their family. The only way to offset this was a balancing act by the Emperor having many concubines so that no one lord outside could consolidate power over the Emperor. If an Emperor didn't have a concubine the lord's would protest over and over until one was brought into the harem. If the Emperor was weak in power he would often bring in a concubine/wife from a powerful family to help him get power. You could also have a weak Emperor that is very young being forced to take a corrupt lord's daughter as his concubine. Then the Emperor becomes a puppet king. This is why you are seeing the Emperor leave the poisoned concubine and their son. In those days any women that had a scar was not allowed to sleep with the Emperor ever as they were seen as defective coming into the palace. Yet if she was harmed while in the palace her status would immediately drop. This link has a video that tells about the concubines of Ming China. https://www.thearchaeologist.org/blog/the-filthy-secret-lives-of-imperial-chinese-concubines

You r very right (☆▽☆)