I think unless there is a clear puzzle and advantage to the players it is not an alternate reality game.

It appears they are just selling clothing and seeing if they can get media coverage. How is that a game?

Hmm, it doesn't necessarily need to follow other game design rules. Sometimes the point is just to figure out the mystery.

When the mystery is deliberately and artificially constructed with such a focus on swag, personally I’ll need more convincing before exerting much effort. There are innumerable legitimate mysteries to pursue.

Great - not participating is and was always an option. But this does not mean it's not an ARG.

a few entry points:

Call some of the phone numbers

Register for a visitor pass

Log in to the Intranet

Apply for a job through the onboarding portal

Also, the "merch" is a regulatory requirement. All property owned by Del Complex that has been declared as surplus is required to be sold and dispersed by the Del Complex Property Office to government agencies, qualified non-profit entities, and the public.