Good points all, and this really isn't something that annoys me too much, it just seems capricious when there are so many other worthy options out there since Season 1.
I suspect it might also be related to this, courtesy of the most recent HH Q&A:
In an answer last time, you mentioned that the upcoming Vintage Collection Magnaguard was originally scheduled for another round of now-cancelled Droid Factory packs. Are there any more figures from those cancelled sets that will make their way into the line somehow?
** Excellent question. The answer, right now is "no" but not for lack of wanting to include more of the figures somewhere. Most of them, however, were firmly EU figures (drawn from the comics, for the most part) which does not leave them a lot of options for homes right now. There are some great figures in there, and we will keep looking for ways to bring them out, though. Stay tuned!
So who knows, maybe he was slated for another line and got scrapped, so TCW wound up being the most acceptable home. (not sure how far along with tooling/sculpting they may have gotten, maybe it was an easy switch)