We'll get the anime ost?

[Newgel]

I don't know if that's a trailer only thing but if it's in the game they're goated for that

[eli_GO]

In Dragon Ball FighterZ the anime OST is part of a DLC and in Dragon Ball Z Kakarot only some tracks are included in the base game but are only heard in the game's cinematics.
In Japan and other countries there is an edition called "Sound Ultimate Edition" of Sparking! ZERO and I guess that in there will be the music from the anime. In conclusion, I would say that they will not be in the base version, at least not so that you can use them freely.

Link to the "Sound Ultimate Edition":
https://store.playstation.com/en-sg/product/JP0700-PPSA15207_00-DBSZ0SOUNDULT000

You can also see this edition at the end of the Japanese trailers for the game

EDIT: Reading the description of this edition it specifies this:

'*The Anime Music Packs allow you to change the battle music and Sparking! Mode music to the anime theme songs like "CHA-LA HEAD-CHA-LA" and music that played during the anime!'

So no, you won't be able to use the anime ost whenever you want if you don't have this DLC. Now the question is, will they use the anime ost during the story mode? I don't know, but if they follow Kakarot's path maybe they will.