No doubt the supply chain issues coupled with high demand is causing problems for every camera maker. This has led to virtually every camera maker at one time or another announce that they're discontinuing taking any additional orders for a product. It doesn't help that such proclamations are often subsidiary specific, yet due to the global nature of the Internet, the media impact of even a regional discontinuation becomes global.
All of the camera makers have intermediaries between themselves and the customers: distributors and dealers. Most of the order suspensions are targeted at those groups, effectively telling them that the manufacturer can't supply that product at the moment. There's probably a legal component to this, but there's absolutely a sales planning component. Dealers can't just sit on their hands waiting for a few products to show up, they have to continue selling something, and dealers need to manage their cashflow carefully.
Thus, a dealer knowing that Product X isn't going to be available for the immediate future allows them to adjust their inventory ordering, plans, and promotions. The two regions where a manufacturer-to-distribution suspension announcement happens most often are Japan and the US.
Sometimes we also see manufacturer-to-customer suspension announcements, though more often we just see more generalized "apologies on not being able to deliver to demand" statements.
In essence, both types of announcements essentially just one thing: wait.
So the relevant question is whether or not they accomplish anything useful.
I'd argue that they do not.
What I find happening a lot now is that when someone gets frustrated by Company A not being able to deliver, if they see that Company B can deliver the (near) equivalent product(s), many customers are now bolting to the other brand. The Sony A1 and the exotic lenses for it are generally in stock these days, but the Nikon Z9 and it's exotics aren't, with the exotics now on "order suspension."
Customers either are buying for "wants" or for "needs." That later category is completely turned off by order suspensions. Their need is immediate, so if Sony has the goods and Nikon doesn't, that's going to turn into Sony sales. It's a good thing that Canon and Nikon have longterm legacy customers that are brand loyal, because they'll at least have some customers for the product(s) in the future when they can deliver it(them).
The problem with the order suspension messages is simple: not enough data. The only data point is "we can't deliver." Even that's somewhat vague.
Note that Apple has pretty darned good customer-facing order delivery information. If a product can't be delivered today, you'll know approximately when it will be (plus they have a strong track record of meeting or beating that date). Of course, Apple has stores and a Web site that are directly interacting with most of their customer base. Apple knows, down to a few minutes, what their sales and inventory situation is, because they put a huge investment into the information infrastructure to accurately report that.
The camera makers have put themselves into a position where they can't really do that. While they ask dealers to report their inventory and can see orders from them, this system is well known to be fallible. Highly fallible. Moreover, the insistence on pushing inventory that is available through to the dealer doesn't help things. This system is not going to sustain. Dedicated cameras are going the way of the Hi-Fi business: we're going to have very few dealers and a lot of direct selling in the future because the sales volume can't sustain a dealer in every city that stocks everything.
But suspension of orders doesn't play in that future, either ;~). Issuing such vague announcements would just make for more brand dissatisfaction. If you can't reliably give me a date on which I'll receive my product, I'm not going to order it.
What we need is clarity. The only form that can take is to provide details as to what the problem is, how the problem is being addressed, and when the problem is likely to resolve.
Imagine a world in which Company X said "We apologize for any delays in delivering your XYZ. Demand for this product is running (far) higher than our production capacity at the moment. Under current conditions, if you order an XYZ today we estimate you would likely receive it in xx days/months at current demand levels and production capacity. While we are adding to our production capacity, this is not something that can be done overnight, thus our estimate as to when you might receive the product."
Or maybe "We apologize, but we've run into a part supply problem that will delay us being able to deliver your XYZ. This has effectively reduced our production to a fraction of what is necessary to meet demand. We are scrambling to find alternative part supplies and hope to resolve that in xx days/months. However, if you order an XYZ today we estimate you won't receive it for xx days/months given our current parts supply. Rest assured we are doing everything we can to address this problem, and hope to have better news soon."
Personally, I'd go further if I were in charge. As problematic as it might be to get right, I'd also establish a centralized ordering queue. To some degree, NikonUSA already does this with the NPS Priority Purchase program. However, that only applies to a subset of the customers, and even NPS members are often left in the dark as to when their product might appear. A good queue is transparent. It tells you how many are in the queue ahead of you, and when you're likely to get your product.
In the meantime, I don't believe the current situation is accomplishing anything. The camera companies just look like disorganized fools that can't manage their product and sales process.