Bst simply got eliminated of high lv content. There's no new playstyle. When you want to go with a melee pt, there are better options, faster and safer then bst. It still can be good on low level content, but it's more a hobby now than an endgame job.
For now it has the advantage that many players have good equip and jp on bst, so that it still may be an option to go with a bst group. But this will fade out with the time and you will see pure melee pt, but more often other ranged setups. Bst cannot join any of them, because even if they add gear for bst melee, you would still need different buffs for master and pet.