As long as they gave an estimated timeline to reset expectations, that would be fine. If the expectation is too far in the future, I can either be fine with it or cancel. Not being told anything seems a bit leading and disingenuous, kinda like they are afraid of losing orders based on uncertainty, which they might, but they also might build more goodwill be being forthright.
We own a company that builds airport service equipment (tugs, stairs, baggage loaders, etc) and we have been impacted by supply chain issues of various types and magnitudes. The reason we have not lost orders is that we communicate with our customers and revise expectations at the same time. If those expectations prove to be wrong, we revise them and inform the customer. They generally understand the delays and we build a bit of goodwill by telling them what we know at the time and always tell them that "our current expectation is xxx, but that could change if....". We have several pieces of equipment that sit on the lot, waiting for a small part to arrive and we let our customers know that as well.
In my opinion, good companies communicate.
As far as I know though, there has been no speculation with respect to parts shortages/supply chain issues on the Gray/Mojave cars and they are producing red, black and white cars. I can only hope they do not run into those issues by the time the get around to grey/mojave, but since they are using their parts supply on red/black/white cars, I am going to be royally perturbed if they run into a parts shortage/supply-chain issue that is non-color specific by the time they get around to grey as they appear to be prioritizing color over order/confirmation date.