Is “Abandoning Shang for Zhou and offering remonstrations” true?
attested in history
The Discourses of the States, Jin Yu IV, records that Xin Jia was originally a minister of the Shang dynasty. After remonstrating with King Zhou seventy times without success, he defected to King Wen of Zhou and became a founding minister. The novel's portrayal of his role as a remonstrating official who defected to Zhou is based on official history.
Xin Jia
In official history, Xin Jia was a minister of the Shang dynasty who, after remonstrating with King Zhou seventy times to no avail, defected to the Zhou and became a key minister. The novel retains his background of abandoning Shang for Zhou but adds a layer of immortal and military campaigns.