I know the point that you're trying to make, but I'm afraid it's not valid.
If you're not shipping from stock, you're taking preorders, whether you have the specs are not.
This is only fair, because anyone can say "we have the specs" and "we've taped out", even though they don't and haven't (see BFL, BA).
I'd disagree on that to a point. If the spec is known on a chip but a product hasn't been finalized and produced, I would agree that it's still a preorder.
Once you're producing and shipping them, if demand exceeds supply and you run out of stock, sales going forward would be backordered. That's pretty standard in every other tech industry that for an existing product if it's not in stock it's backordered.
The problem with preorders is that they shift the risk of development onto the customer. Any delays in the development cycle (or underperformance in the final system) are usually borne without compensation by the consumer. A backorder is different since the only real risk is meeting production and shipping deadlines.
If SP (or anyone else) runs out of product and advertises it as "not in stock, usually available in 2-4 weeks" that's no longer a preorder, and if they miss the stated timeframe for shipping that should affect the On Time category, not the preorder category.