Not exactly.
He is suing to be allowed to pirchase the firearm from a specific vendor. He still has every right to exercise his 2A right, even if that means building the firearms himself. Much like I have the right to eat, but I don't have the right to purchase or eat food from your garden.
I realize this is a very simplified example, but I found your post to be grossly oversimplified as well. The suit isn't even related to the infringment of a right, but discrimination.
The two stores are indeed infringing on his right to legally purchase a firearm due to age discrimination. Is that simplified enough for you?
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