The law that he can invoke in a weaponized way is the ADA.
It’s vague enough about what a disability is, that something like “my hand tremor and farsightedness preclude using a touchscreen, I request a reasonable accommodation” is a valid request. If they deny admission and accommodation to somebody incapable of using a smartphone, there is a whole army of lawyers that will gladly take the case on contingency.
As you note, the app is not inherent to seeing a game, or preventing resale. There’s no reason an id and confirmation number can’t be used to get him in.
There is a special ring of hell reserved for people who abuse the ADA.
Such abuse is an insult to everyone who needs it, everyone who engages with it in good faith, everyone who spends gobs of money to make events and services accessible to those with genuine need.
I don’t rule the world but if I did abusers of protective rules would be summarily executed. (Don’t vote for me. I’ve got a short but significant list of similar policies. Scammers those guys would have targets on their heads, kidnap for ransom criminals those guys too)
I don't agree that using the ADA in this way would be abuse.
The ADA was a rare "great" law, in that it is sweeping, applies broadly to many different forms of disability, and it provides companies very little leeway to weasel their way out of complying. It also provides us with a very, very good generic framework for consumer protections, should we ever get an administration who cared about consumer freedom over corporate interests. I'd love to see other (not disability related) ADA-like laws that compel companies to make other reasonable accommodations to be inclusive of reasonable consumers. All kinds of amazing "consumer bill of rights" regulation could be modeled after the ADA.