You'd think that, right? I work for a small design company and we're changing designs daily to work around stock shortages. If you find parts you need to order them within hours, but if management has to OK a large order and doesn't respond until tomorrow, now something is sold out.
For the Pi, they can't change the design to work around shortages. Some components have drop in replacements from other vendors, but not all do. Even when they're supposed to be pin compatible, they might have subtle differences.
And all the ICs (doesn't matter if they're microcontrollers or voltage regulators) are going to the automotive industry.
We still haven't talked about shipping delays. Ports are backed up, ships are over filled and occasionally losing containers into the ocean. If you have any order large enough to need container shipping, good luck tracking that. It can arrive in port and clear in a week or 6.
The Pi foundation is much larger purchaser than my employer, but it wouldn't surprise me if they really can't get accurate timelines right now. Until we (or rather the assembly houses we contact with) have taken delivery of components, we can't say for sure.