It may get cheaper. There’s pills on the way that reduces the costs a lot. If those cost savings make their way to the patient then its cost may offset the additional food and healthcare costs of being overweight.
But pharma rarely reduces costs for the patient. What will likely happen is the pill form will stay just below the cost of the injectable until it’s valid as a generic. Then pharma will do some shenanigans to further delay it from going generic such as convert it an OTC drug in order to keep costs high.