I don't know about the United States, but in Australia this practice is highly illegal - misleading and deceptive conduct under the Trade Practices Act. Selling items they don't have to keep the lights on may even be trading while insolvent (an accountant would know the answer to that one better).
There's a simple solution that would save so much angst on both sides. Add a status of "backordered" and description that says, "Products on backorder are not currently in stock for fabrication. These items may be ordered but the timeframe for delivery cannot be guaranteed. Please contact Ultrasabers before ordering if you would like an indication of timeframes for any backordered items". They could even add something like "Due to the popularity of this product, it sells out quickly. Additional hilts are on backorder...". Gives people reason to get in the queue or risk missing out again if they wait.
Then they can have their cake and eat it. They can maintain their "fasted" fabrication and delivery rep (as backordered wouldn't factor in), they can keep selling these hilts in the meantime, and customers would be more informed and bombarding them with less emails and anger.
Surely that's not a hard implementation?
First ... illegal? Lets stay away from making those kinds of inflammatory remarks. I think everyone can agree that US is doing their utmost to get everyone's orders out as quickly as possible.
And to that end, let me postulate a hypothetical, to hopefully illuminate just how complex this situation is.
Today, I go to the website and I decide I want to order a saber. I look, and after some internal struggle I finally decide on an Aeon V4 LE with Obsidian Lite, a lit AV, and a Consular Green Tri-Cree LED.
And I place my order. On the day I place my order, US just got a shipment of Aeon V4 LE hilts in, so there's a whole bin full of them....
....but there are also a lot of orders ahead of mine in the queue.
So, my order sits in queue for 2 weeks, and the day comes to assemble my saber. Yay! Except there's a problem. There are Aeon V4 LE hilts available, but the last shipment of lit AV switches in the color I ordered was short by 100 units due to issues with the supplier. The guys on the line check, there's another box coming in a week. So my order gets set aside for a week.
The week goes by, and about half-way through the week my order gets picked up again. This time there's an AV switch, and the the hilt ... but now there's no Obsidian Lite cards available. The shipment from the supplier that was due yesterday is late.
Again the order goes back into the queue.
Another week goes by. Then two. Then three. And the Obsidian Lite cards finally come in, a half-shipment, but better than nothing!
The hilt comes down the line again, gets to the assembly, and... No green Tri-Cree LEDs.
And now there's a quandary on the line, because they're running low on Aeon V4 LE blank hilts, which are also overdue from the machine shop. So the decision is made to use "my" hilt to fulfill another order, identical to it except it has a Guardian Blue LED. It goes out the door ... and my order goes back into the queue.
The customer who ordered the blue saber gets his saber in 9 days. He is very happy.
Three days later the Aeon V4 LE hilts come in, but now (again) there is a back-order on the Obsidian light cards. The manufacturer of these cards struggles to get their orders out, and finally gets it out 5 weeks later. They are over a month overdue.
All parts now in-hand, my order comes up in queue again and the saber is assembled and shipped.
I've waited 11 weeks for my saber, but it is finally on the way.
Now.... At what point did the Aeon V4 LE go out of stock? Even if US kept the website completely up-to-date on a daily basis on whether the green tri-cree LED, or the Obsidian Lite board, or the green lit AV switches were in-stock or not, it wouldn't have had any effect on my initial order.
These are CUSTOMIZED orders. They are built to-order, and there is some lag between the order placement and fulfillment. As I said before, there is no cure for this except patience. US customer service is doing their best to keep people informed when there are delays, but they're also a small specialty shop. Bear that in mind when you start wondering why they're not doing this or that.