It would absolutely represent either a mis-estimation of demand or compromise to some supply/manufacturing bottleneck that they couldn't overcome without sending their release calendar into chaos.
Those are hard-to-beat features for typical Apple users, for sure, but this is aiming for a different niche and the potential buyers in that niche may not be as concerned with form factor or power draw (for instance), and some may even see the OS as a negative factor. Those are just factors that happen to come along for the ride since it happens to be an Apple product.
Did you know the McRib is back?
But only for a limited time so you better act fast!
When the M3 Ultra 256GB+ models got discontinued the secondary market prices went through the roof. That's not manufactured demand.
All the M5 Ultra Mac Studios have had 3-4+ month delivery estimates within a short time of launch until now. I occasionally check and noticed that the 96GB model has moved up from February to December where I live (pickup or shipping). There's clearly a demand for these things and it's widely believed it's largely AI.
That doesn't really matter though for a physical product, unless you are implying they are 1) selling it at a loss or 2) not attempting to maximize profits from the product. If they sell out, it means they hit the target profit from the sale of the product.