Yes, most often the hands stop working before the end. Some people can use some other muscle to work the wheelchair, such as a pillow switch, head control, or eye gaze, but any of those are difficult. And even if someone can control their chair, feeding, toileting, taking the mask on and off, etc. generally all are things that require assistance as the disease progresses. For most PALS, all voluntary limb movement, along with the ability to eat, drink, speak, and breathe unassisted are gone by the end.
In Illinois, the largest support organization is ALS United Greater Chicago -- you can find them on line. If your brother is outside their service area, they can recommend resources wherever he is.
Where was your brother diagnosed? The way you have described the process and the statements made is troubling. ALS is a clinical diagnosis and one meets the criteria (including testing) or not. It is also a diagnosis that requires a second opinion depending on where the first was rendered.
I am not saying he does not have ALS, but you seem to have doubts and I wonder if he does as well, which could relate to his ambivalence toward interventions to extend his life.