I'm very happy to consider the possibility that he is entirely truthful in what he says. It also occurs to me, that perhaps he knew (or simply suspected) ahead of time that some bad things were being planned, and perhaps this was his way of getting the information out to the public, whilst framing it within a fictional story.
I don't think he knew anything regarding any plans. I believe his claim that he was able to tap into some kind of field, and was bombarded with information regarding possible futures. Simply based on his authentic personality.
When you look at authors who are part of the elite, than you will see figures such as Aldous Huxley. In my youth, I've read his books and I was a big fan. When I came across a quote where he said something like "Finishing a book is always a nightmare for me, I hate writing", I didn't think much about it, but later I realized, it was just his job. He had to do it, because writing was a tool for him to get his propaganda out.
For Dick, writing was his entire existence and his life. It was the only way he could make sense of his visions. Especially as he saw a lot of nightmares.
Is it possible that he was some kind of experiment where he was chosen to receive information? Probably, but if that was the case I think those who did that were likely not human, but aliens as part of the "hyperdimensional" control system. And that's also why one should take his stories with a big grain of salt. These stories are likely not our future, but what certain entities want our future to be. That's why they turned every good Dick story into a blockbuster, basically. He saw technocratic nightmares where human individuality was destroyed, and freedom eliminated. I don't think thats our future.
His visions are way too technical, and cold. There's missing something for me to think he saw humanities real future. The visions got beamed into him.
There are reports of many historic visionaires in Europe and Germany, many of them faithful Christians, who reported they were given the future, or the possible future, of humanity. And many of them see similar things - a third world war (with Russia invading Europe in summer), three days of darkness, a spiritual battle, a cleansing of evil, etc.
These visionaries all imply that some time after the second world war, there will be a short third world war, one way or another. They often mention that humanity has degenerated pretty much right before the start of the war (feminism, dissolving of the sexes, materialism, etc.). The short war is directly followed by a short period of darkness which is aimed at initiating a new golden age kind of era of peace and freedom.
If Dick's visions are objective visions of our future, one should ask why he was the only one who ever saw them. He's likely a tool used to sell us the technocratic future where humans are completely attached to technology, and don't have any freedom left.
While the historic visionairies are also a bit questionable, at least there are many of them with similar visions (cultural degeneration, then a war plus cataclysm, followed by return to god).
