Yeah, they know Robert Ford.
I mean the scenario presented by the show is that Ford worked with Arnold and a small team for 3 years before the park was ready to open. We don't know how public this is, so it's not impossible that the beta period was meant to be a secret project to attract investors. We don't know what the scientific community knows about the facts of Westworld's origins, we don't even know anything about the state of the world at large. If we keep going down the rabbit hole, then the biggest question I have would not be how they covered up Arnold's partnership, because that part is really easy. It would be how Westworld even got made as it is, without Delos outright owning them from the start. Where did the money come from? The land, the tech, the details, and 3 years of R&D and production without seeing a cent in return until the park opens? That's a shitload of money. What did Ford do before Westworld?!