Tekken 7 will keep the tradition of the series by adding secret and unlockable fighters for you to obtain.
Tekken 7’s director Katsuhiro Harada confirmed this on twitter in response to a fan’s question. He said “we’ve unlock(able) or secret characters”. Several previous games in the Tekken series did this as well. Normally half of the game’s roster is locked and you need to beat the Arcade or Story mode with different characters to unlock them all.
2012’s Tekken Tag Tournament 2 was different however as every fighter was available from the beginning. The only thing you needed to unlock were the ending movies and clothing items to use in the customization mode. It appears Tekken 7 will be like the main games of the series where you need to earn the right to unlock more fighters. This isn’t a bad thing as it can be quite addictive trying to unlock every fighter and gives you more reason to play the game even more.
The only fighters revealed to be in Tekken 7 so far include Kazuya Mishima and Heihachi Mishima. The wife of Heihachi and Kazuya’s mother Kazumi Mishima plays an important role in the game as well. Tekken 7 will conclude the Mishima saga which means Tekken 8 (if it’s made) might focus on new characters instead.