If it was believed that they be purchasing N, then that belief was priced in. If they only bought N-1, the price needs to be adjusted to reflect the new information.

Here, the argument is "the more hardware we have, the more compute we can sell, the more compute we sell, the more profit we'll have" and so investors were expecting a higher level of profit and now are not.

All of this is why stock value and company value often share little with each other. The people working at the company and the people investing in the company have different views of what one small piece of the company is worth. You'll see PE ratios vary by sector, over time, by strength of underlying economy, near lows/highs etc. Any company's value is only set by what people are willing to pay for it at any given time.