#1 The New Day will not defend their titles at the Royal Rumble
Kofi Kingston is Mr. Royal Rumble. It is almost 100% certain that he's going to be a part of the Royal Rumble match this year, in some capacity. And that makes me think that the SmackDown Tag Team Championships will not be defended at the Royal Rumble.
Even if you look at SmackDown as a whole, there is probably no team right now which can contend with The New Day for the Championship. Heavy Machinery are babyfaces and we've seen far too many matches between The Revival and the champs.
A top AEW star just called one of his colleagues 'spoiled' and 'narcissistic' HERE.
I guess with Sami Zayn returning, we could always have him team up with Cesaro to take on The New Day, but that's a really strange team indeed. And I doubt that Cesaro will be teaming with the returning Sheamus to take on The New Day because that will be a step back for Sheamus.
So, maybe the only thing the New Day does at the Rumble is participate in the actual match.