#5 First woman to win a SmackDown pay per view main event
The decision to headline the TLC pay per view with the triple threat match between Asuka, Becky, and Charlotte was the proper one. It was still surprising nevertheless, because WWE is notorious about letting Raw matches main event over SmackDown ones on a dual pay per view. See Backlash for the most infamous example, where a random Roman Reigns vs. Samoa Joe match headlined over the WWE Championship.
Sure, the Ronda Rousey intrigue that came with this match was probably important in its consideration on the card, but even without her, it would be hard to justify any other main event.
Asuka's victory to close the show was therefore a historic achievement of another kind, bringing some prestige to the blue brand. It also meant that Vince McMahon trusted that Asuka would be well received in her victory, which she was.