[THEORY][SPOILERS]What we just witnessed was espionage going right, until it all went wrong.

I think whoever has been doing stuff as Arnold - the reveries update in general, modifications to certain hosts (the woodcutter, Maeve, assumedly Dolores, maybe others), all of that - was all part of an espionage plot to get both intellectual and physical property out of the park, and to dethrone Ford.

And it seemed to be working, for the most part. Ford fell for it hook, line, and sinker, thinking Dolores was the main event, because that was who Arnold favored. (But it was really Maeve. But more on that after). And they knew the Man in Black would be there to further complicate things. From what we have seen of Ford, he keeps himself amazingly well-composed. The surprise of the reveries update was revealed to his face and he didn't skip a beat acting like it was all his doing. He's never shown anger that I can think of, or let on when he's the one probing for more information. He didn't even flinch at seeing Bernard again. So I think most of what Ford was doing has really been in retaliation to "Arnold", his whole new narrative was his attempt at trying to turn the tables, culminating in the massacre as a last resort, the ultimate "fuck you! If I'm going down, I'm taking you all with me!", poetically using the Wyatt code Arnold himself wrote.

And then there's Maeve. The grand prize, the goal of everything. With the help of the reveries update, she was programmed to become self-aware, and effect an escape from the park. But the reveries maybe worked a little too well...maybe they weren't completely aware of her model's predispositions. She went to cold storage to see Clem (an unplanned event, but which wouldn't have meant anything except she discovered Bernard). Then, when she was finally on the train, she found she couldn't leave her daughter behind. This was the real moment of her finding sentience. Her programming was for her to go to the mainland (likely walking into another trap) - that's why everything shut down as soon as the train left.

Isn't it ironic, don'tcha think?