Seems as if HBO is being much more conservative in terms of renewing shows; West World is about 60%-70% done at this point and they are just now getting renewed for another season; it years past I remember HBO renewing shows a lot sooner.

I also remember this show being delayed because the show runners were planning out future seasons, so it's a bit weird to hear the show won't be back next calendar year because the scripts for the second season aren't written yet.