@Douglas H t is not surprising to exclude laptops from an iOS centric event. Those are more likely to be released in October, and perhaps without much fanfare.
You are correct, but an Event have cost. A second Event one month later (or 5 weeks)…
Unfortunately, we do not know the ins and outs and can only make guess based on rumors ;).
Rumors are just rumors, even if at one point of time it can be true. A product can be stopped under conditions (not ready, last minute discovered bug, etc.) and that explains why some appears later or never.
At last, we have to remember that an announced product have to be released withing a certain amount of days after the announcement date (90 days ? less ? I forgot.).