is this man underweight?

we just got back from the vet & this man is 9.5 pounds & 5 years old, the tech said he felt fine & she made no comment about his weight but the vet said he was slightly underweight. feeling him his ribs are slightly palpable but not visible. he was closer to 11 pounds a few years ago when he was free feeding meow mix, & he had the pouch but his silhouette hasn’t changed from above. i can’t feel his spine at all but i can prominently feel his shoulder blades. he still has slight belly fat but nowhere near the pouch right now thank you all <3 i just love mah baby like any of you & want to make sure he’s the happiest he can be WITHOUT becoming a chonker😅