So regarding the Future Weapon Battles (Future Patches)

[DevilsDontFly]

I wouldn't expect more than 2 other fights (one of which will clearly be Sapphire)

3.x had three "side trials" of Sephirot, Sophia, and Zurvan
4.x had Byakko, Suzaku, Seiryu

SE loves their patterns and all.

They might do what they did with the previous expansions, though.
Originally, it's Byakko, Suzaku, Seiryu and Genbu. But Genbu was the last boss of a dungeon.

I also recall that you had a solo duty in order to progress through the Warring Triad questline either before or after fighting Sephiroth.
I'm assmuming it's going to be the same thing with the weapons. Ruby, Emerald and Diamond being main trials while Jade potentially being in a solo duty, side dungeon or something else among those lines.

[VenKitsune]

They might do what they did with the previous expansions, though.
Originally, it's Byakko, Suzaku, Seiryu and Genbu. But Genbu was the last boss of a dungeon.

I also recall that you had a solo duty in order to progress through the Warring Triad questline either before or after fighting Sephiroth.
I'm assmuming it's going to be the same thing with the weapons. Ruby, Emerald and Diamond being main trials while Jade potentially being in a solo duty, side dungeon or something else among those lines.

Genbu was only a dungeon boss because that dungeon was required to unlock the others. We've already unlocked ruby weapon, that boat has sailed, because this expansion all of the dungeons we're getting are MSQ based, which means this wont be happening.
A solo instance might be a possibility but i HIGHLY doubt it - Ultima is one of the few fights in the game that the WoL didn't canonically fight solo, and so we can assume Ruby wasn't either considering Gaiuses claims that it was just as powerful, if not more so than Ultima was, so naturally the WoL would bring along help, so it wouldn't make sense for one of the weapons to be a solo instance.

[DevilsDontFly]

snip

I meant more in the sense of: Setting aside FFXIV, you had Byakko, Suzaku, Seiryu and Genbu. So if they planned only three trials, their way of including all four was through making one of em part of a dungeon that ties the story/characters together, as it would be weird to have only Byakko, Suzaku and Seiryu with no mention of Genbu.