First of all very cool trailer! I liked very much the fact that is not just for "commercial" purposes but it's clearly made for whose into the lore.
As you said, I too think that Amaranta it's at Wanda's side, my only extra thought is whether she is cursed too now, I guess we can't know. Not sure if all this is also tied to the murder mistery we're gonna be discovering in the coming months. I think the first thing every one thought of as soon as we discovered the first Mistery was a murder with an important character as the victim was "someone in the Arena is gonna die" which instantly makes you think "Amaranta hates de Marco and Lesedi" but people like the Pirate Lord himself got murdered and could die because the Ferryman wasn't there to bring him back from the Sea of the Damned but instead the "phantom" of Ramsey somehow escaped the Sea of the Damned.
So, how does a murder work now? What if Amaranta was actually the one that got killed, what if someone intentionally cursed her and that kinda counts as a murder as skeletons count as un-dead I guess.
Also loved that the fact that Flameheart can't be seen in the skies got underlined, suggesting he got revived or the ritual to revive him is happening right now.
The Servant of the Flames wants Wonda, perhaps the plan is to lure Wanda somewhere or he thinks Wonda is as skilled as Wanda in terms of working with iron and curses.
Wanda is clearly angry, possibly wants to save her sister with her own hands, the fact we've seen her might mean that the choice we'll make in the 3rd Adventure might be choosing between Flameheart and Wanda's crew (/Dark Brethren, I'm still not sure if the Dark Brethren kinda broke up after Davy Jones defeat).
PS: Also, Wanda's ship is Barbossa's (meant to say Dark Warsmith) ship set?