For small runs it would be good to make your own handles to keep costs down so we can get more releases. Re releasing desired fixed models without handles is a win win. Pre pay for the model you want and Spyderco can adjust the numbers. They can make runs in different steels of the same model too.
Keep in mind the Aqua Salt was a stick tang with the FRN handle injection molded on. Making your own handle would not be a simple or easy task. With the Mule Team, you have a full tang with a bunch of holes pre-made, so making your own handle is relatively easy. Even so, how many actually do, and how many buy scales or just cord wrap the handle? Any further runs of the Aqua Salt are going to require a total redesign or investing in new molds for a model that didn't sell well enough to justify that cost.
This mirrors my own thoughts about bare-tang knives. I would wager that the afi’s with the skills and inclination to make their own knife handle are vastly outnumbered by those who won’t do that but will happily pay for a handle that is already made.