Usually if a Nintendo Direct is coming, NCL has to make a new slot available on their ND pages (and if there is something indeed coming, NCL pulls the trigger and orders the Nintendo Direct announcements which forces NoA and NoE to make ND pages for the upcoming direct -- provided if the ND isn't region locked).
So what do you think will happen? One more ND before the end of the year recapping all the "most haves for the holidays" with maybe a little tease or two for early 2018? Or will they wait for the actual 2018 to start before bringing a new ND to the table? Your guess(es) is/are as good as mine.
My guess if it's one more ND before the year's end:
1) They'll recap all the must have holiday titles and bundles of stuff already released or just released.
2) They'll recap AC: Pocket Camp.
3) They finally announce Nintendo Switch rewards on My Nintendo.
4) They tease a The Legend of Zelda mobile spin-off mini-game for 2018 that ties into Breath of the Wild.
If it turns out a new ND for early 2018 instead, then I'll suggest guesses #3 and 4 for this one along with announcing and reannouncing spring stuff for 3DS and Nintendo Switch.