Katsuhiro Harada, the man behind the Tekken series, has released a statement regarding issues from players who are receiving copyright strikes due to video game music.
In general, one cannot use another person's music or material in their video, however, exceptions are made if the use of said material is transformational, or for education purposes. In the case of video games, the music which is usually playing while the player is accessing the game, is generally safe to use. However, it seems players have run into problems while simply playing the game with the music on.
Recently, there has been a lot of complaints from streamers who are simply playing the game with the music on and they get a strike due to this which has led quite a few people to opt for turning off all the sound from the game while streaming.