Don't run so far ahead, there are too many rumors and little information.
As for Brant - I will personally leave my thoughts and so to speak, we will see how right I will be in the end on release. Healing in this game has an extremely mediocre value, as well as shields (well, at the moment, based on what is in the game), it makes moving around the world map more or less comfortable and nothing more, if we take the endgame - Holograms 5 - 6, Hazard hazard zone, then there it practically does not matter, since the same Holograms are made in such a way that they kill you with 1-2 hits and healing is simply useless here. What is really important is the volume of buffs and the strength of the buffs on the Healer and his rotation, even their element does not matter at all since they do not geared for damage and they will not inflict it in principle, they appear on the battlefield for an insignificant time, give out their buffs and immediately leave. Now in the top two characters are Shorekeeper and Verina actually why are they there, oddly enough not because of the healing, as I already said a nice bonus that makes the open world more enjoyable, but because they are very strong damage buffers and most importantly their buffs are universal, so they absolutely do not care what element the characters with them in the group are.
As for Brant, everything will depend on his buffs and how strong they are. His downside is that his damage buff is strictly tied to Fire damage, which sharply reduces his versatility, so it seems to me that he will be lower than Shorekeeper and Verina. How much lower he will be by 1 or 2 lines will depend on the strength of his other buffs.
Another question is that the release of Brant is associated with 2 interesting questions and interesting options for the development of events are possible.
1) If his Fire damage buff is strong enough and there are no problems with rotation, there is a chance that we will have a new meta team Encore + Changli + Brant, if the buff is serious - Encore can even move up 1 line as DPS
2) But this is pure theory, they have in the near future plans to release a new fire DPS and that will be a completely different story....
But as I said, all this is purely my thoughts, and I may be wrong.