Sideshow are hoping it will be the next 'big' thing and that they can make a fast buck. If it happens to go really well, then they will do more, if it goes pretty average, they will let it die.
I think the Disney PF line is a clear recent example of how Sideshow will do things. Start with a big announcement, in the first year have 5-6 items previewed, pre-ordered or even shipping. Wait to see if it really all sells out fast, delivering quick turn-around and fast profits (all the Disney PF's are now sold out, it just didn't happen fast).
If it's a slow burner, then redirect development cost's back to Star Wars, Marvel, DC and wait to see what the next big thing maybe and do the same again. Say nothing about the state of the line they were so keen on and just let it die out.
Middle-Earth isn't exactly in that pattern, but I think Weta getting the 1/6 LOTR license back, along with I suspect a slow down in sales of their current LOTR items has resulted in a pause for thought and where best to spend development cost's for the greatest and fastest profit return.