This is not correct according to the article by Ctein.
Overwashing of RC prints led to the problem which was caused by atmospheric effects. By reducing the wash, Ctein showed that small amounts of Sulfur were retained, which by forming Ag2S helped stabilize the image. This is similar to the effect of Sistan and Ctein showed the relationship.
However, one must treat image stability (Ctein's study for example) apart from the stability of the support itself. Early RC supports tended to crack after years of exposure to the sun and to the atmosphere. In most cases, the images were fine.
After about 1970, the RC papers were fine and image stability was fine for B&W prints as long as they were not overwashed.
PE