DarkSkies is Apple providing metadata for a FUTURE title …
Correct
DarkSkies … that makes SF think it CAN be downloaded NOW?
Looks like SF can’t read/understand the meaning of “comingSoonDate” in Apple API

So, in the case of series, in addition to the first/current episode,
the last episode would also have to be analyzed,
but this is obviously not the case.
So I think SF use only a “link grabber” and the future link
will also work a week in advance (if unfinished - s01e09 here)