#3 The Usos win via a disqualification
If you look at the tag team landscape of SmackDown Live, there's literally no heavyweights to carry a program on their back except for The Usos and New Day. WWE may just want their program to continue for a really long time, maybe even over months.
The easy way to book this match would be to have one of the members of The New Day interfere in this match and cost The Usos the titles via disqualification so that they win the match but not the championships.
Remember that while The Usos are the heels, The New Day have a numbers advantage, even though they are the good guys in this case. If it meant retaining the championship, using the numbers game to their advantage is something you would expect from The New Day.