Interesting that they didn't announce another guest character like they've done for each season, some people think it's so that they don't steal Soul Calibur's thunder with the Haohmaru announcement. In any case as a massive Tekken fan who played Zafina a lot in 6 and Tag 2 she looks super cool, especially with Azazel's arm, and Leroy Smith looks pretty cool, i've seen people thinking he'll play like Wang as they have a similar style, but i'm pretty sure he's going to be fresh (side note, all the black characters in Tekken 7 have dreadlocks apparently :P).
It's probable that one of the techs behind the scenes put it together as a joke that only he found funny, such a weird thing to do, they were literally about to show the official reveals. You can get a little glimpse of these two in the new trailer below. This Winter will see the addition of a new, original character named Leroy Smith. Tekken 7 Season Pass 3 will add in Zafina, a "spiritual warrior." She will arrive in September.
On a very related note, Bandai Namco did reveal two new fighters that are actually coming to Tekken 7 this year. In one thoughtless act, EVO somehow managed to upset fans, Katsuhiro Harada, David Hayter, Bandai Namco, Konami, and even Cameo. Harada even went so far as to say that he feels sorry to both Konami and Hideo Kojima, even though he and his team had no hand in this.
Tekken series producer Katsuhiro Harada also voiced his disappointment in a series of tweets today. And as this was done only by EVO, the fault lies squarely on their lap. The video shown at EVO promoting Tekken could very, very easily be considered promotional material. Unfortunately for everyone involved in this stunt, the Cameo Terms of Service say that you cannot use any recording for promotional purposes.