After all, even if Jiang Yue was pregnant, she had not given birth yet. Who knew if it was a boy or a girl? Who knew if it was healthy or not? Who knew if it would grow up into a capable person? Therefore, no one would agree to let Jiang Yue's child inherit the throne while it was still in her stomach. There had never been such a thing in history.
Moreover, a country cannot be without a ruler for a day. Once cousin Xue Yan dies, to quickly stabilize Da Ling, Prince Shou will have to succeed to the throne.
Prince Shou was also her aunt's son, and he did not have much of an impact on the Shao family.
However, it would have a great impact on Jiang Yue. If Jiang Yue's child could not inherit the throne, she would not be able to become the Empress Dowager.
Prince Shou would marry an Empress sooner or later. As the saying goes, two tigers cannot live on the same mountain. Even if they did not have the same husband, the situation would be awkward.