Well, I'm still in diapers, but it has been enough to get a view from the other side. Just like retailers get overwhelmed with Pre-orders, so do manufacturers. There are tons of different issues and scenarios going on.
As a collector, I only got an order canceled by one of the small retailers that could not source the model after taking my pre-order. Since then, I have started to order models I really want from multiple retailers.
I'm in no rush to list recent Panda MD-11s for pre-orders for instance, as based on my experience, it is somewhat of a futile move. It is a bit of a "choose your poison" situation and "bird in hand" seems to be the preferred concoction for me at this stage.
I find it interesting that NG seems to sort smaller retailers first, seems like the prefer to pack smaller shipments while procrastinating with the bigger ones. My experience with other brands, both as a collector and as a retailer is the opposite. The best cu$tomer$ tend to get favored. This represents a challenge for new retailers as you sort of have to buy your place in the market in some situations.
But back on topic, I never had issues with Panda Fox, though in my last year, I had been buying mainly from WCA. But I remember PandaFox were extremely competitive, so it should be no surprise that they got overwhelmed. As far as in-stock items still showing as pre-orders, that's also very common and has happened to me many times (I get a model delivered, and the store still shows it as a pre-order). Turns out updating product status usually has to be done manually, and tends to get confusing too, especially when release announcements outpace the delivery of the actual models by a multitude of manufacturers.