There is no right answer

In dealing with folks with massive weight loss there are any number of combinations that can be wored out. The decision is based on  the health of the patient, the risk vs benefits, the desire of the patient of downtime, expense, ultimate best result and other considerations. Some plastic surgeons prefer to do as much as possible all at once, some want to do in multiple stages. You need to sit down with your plastic surgeon and have at least two discussions regarding what your expectations are and how those expectations can best be managed.