No, it's not complicated. No company that wants to sell you something would intentionally make that something more difficult to buy. Apple wants the sale now, not some possibility of a future sale because the product looks "in demand" by being out of stock. How many lost iPad Pro sales have there been because the pencil and keyboard aren't in stock? Do you really think Phil Schiller told Jeff Williams to slow down production of the pencil because showing 4-5 week shipping delay makes the product look more desirable? Dude, you seriously need to remove that tinfoil hat.
With respect, you still have no idea of what you're talking about. Restricting supply increases demand as it increases demand for something that doesn't yet exist physically. Insane people will queue for something if they believe there is limited demand for something that has been hyped.
It's standard marketing practice and this is what I do for my job, albeit in a different way.
If you want another example, take the PS2. Sony had "manufacturing issues" and weren't able to supply enough units in the week it launched. However, it was all about creating demand for a new product. Units were shifting for 3-4x the RRP and people were clambering to get their hands on it.
It's just what big corporations do. No tin-foil hat is needed.