Why was the completed Sikuquanshu revised after Qianlong reviewed it?

The Sikuquanshu (Complete Library in the Four Branches of Literature) was revised after its completion because the Qianlong emperor discovered texts within the compilation that he considered seditious.1

The project, which aimed to catalog the most important works of Chinese learning, was conducted alongside a broader campaign of censorship during the Qing dynasty. The emperor ordered the expurgation or destruction of books containing anti-Manchu declarations or allusions. When he identified such material within the Sikuquanshu itself, he ordered revisions to be made at the expense of the compilers. This effort to control the intellectual landscape and suppress dissent was a significant, albeit repressive, aspect of the Manchu court's cultural initiatives.213