I'm not even sure I would want BST in FFXIV because I don't think it's a very good fit for this games design. It really needs areas that are far too dangerous for other jobs to wander about solo, and the open world is too tame in FFXIV.

When I think back to the times I really enjoyed BST in FFXI I think of,

1. Solo leveling with charmed mobs when the job was completely shunned by parties. BST had it's own camps, it's own leveling area's, it's own version of the leveling grind that was unique to BST. Solo BLM on mob BST pets was similar, but different mobs and area's.

2. Soloing Dynamis after it got it's revamp, thf could /dnc and just about get away with it but BST excelled in there, especially as jug pets had become default by then and you could get TH1.

3 Soloing Abyssea, all of it. I did the cats, the zone bosses, almost everything on BST. It was especially fun if you teamed up with a SMN as the pet could tank and the summon could do the dmg. You needed a party of 6-8 people at that time to do what a BST could solo, and a BST SMN combo could destroy, it was fun.

I just can't see how any of that fits into FFXIV, and it's what I personally found fun and attractive about playing BST. It would be disappointing to me if they did introduce BST and it was just a melee version of SMN or even worse, a limited job.