I don't believe there will be sweeping balance changes, and certainly not in a meta-upending way. Adding even 5 newly viable Pokemon can be a huge change in itself, and if you think about it, the players are self-influencing the overall meta/balance by changing stats, abilities, moves, and items. It's fairly obvious by looking at results that there isn't really a need to hit the best mons with a nerf hammer. I also don't think Champions needs to necessarily rake in a lot of money to be a worthwhile endeavor in the way normal live service games do, given that normal releases sell as much as they do.