Is the suspended divorce of the wife effected by the husband marrying another woman, if the husband marries another after her disobedience and her and her guardians’ refusal of reconciliation, knowing that the husband suspended the divorce with the intention that the wife would continue her good treatment and fulfillment of her marital rights?

It appears that you wrote to your wife that she would be divorced if you were to marry another woman. This is one of the "kinayat al-talaq" (ambiguous divorce pronouncements) by which divorce does not occur unless intended. So, if you intended for divorce to take place merely by marrying another woman, then it becomes effective; otherwise, it does not. The occurrence of a conditional divorce upon the fulfillment of the condition is the view of the majority of scholars. If your intention when writing was to restrict the divorce to her continued performance of her marital duties and her not being disobedient (nashiz), then if she becomes disobedient, your intention benefits you, and her divorce does not occur merely by you marrying another woman, because intention specifies the generality of the wording.