Ok so I have to apologize again for posting a rather desperate answer to the Olicity problem I posted the other day, I was feeling rather down at the time. Sorry if I caused any anguish. That said there is something I want to point out to everybody in the new trailer and how it could have implications that hopefully do give us what we want. I re-watched Legends 1x06 as well and there are a few hints that Felicity may not be alive as everybody keeps assuming for a couple of reasons.
In the trailer there was no Felicity in the post-Lian Yu scenes yet they spoiled Slade, Dinah and Laurel? I know Thea, Curtis, Diggle, Quentin and Rene were also absent but you’d think they’d just get the suspense out of the way since this is their precious FeFe we’re talking about and just show one scene with her, even one second just to reassure fans of what everybody is expecting. It could be a way to keep things secret for general viewers but there is nothing to indicate Slade, Laurel and Dinah had any greater chances of survival than Felicity and they’ve straight up spoiled that they don’t die. However that's not the main reason I think she may yet die.
The main thing that’s got me suspicious now is something that I think many people may have missed. Oliver in the post-Lian Yu scenes is using a different bow. He’s ditched the one he’s used since season 2 which Felicity had “custom made” for him, which I believe he described as being "perfect". Every time he’s lost or broken it, he’s always had it fixed or replaced it with an exact duplicate of it as it clearly has sentimental value to him given that he “loves” Felicity. Even when he abandoned his Hood/Arrow title and finally became Green Arrow he still used the exact same bow. Oliver has lost a lot of people and none of them, not even Laurel, made him want to change his weapon so why change it now? Maybe it’s too hard because it’s a constant reminder of his dead love killed because of a monster that he created? Further evidence is the events of the Legends episode Star City 2046.
In the possible future of Star City where Felicity is still alive in 2046 Oliver still used the Felicity-bow which demonstrates that whatever motivates him to change up his choice of bow in 2017 never happened in this timeline. So it’s possible that Oliver never encountered Prometheus or he did but it ended differently. It could be an oversight but I think the producers do put more forward thought into the shows than people think because the suit Oliver is wearing in LOT 1x06 is his season 5 suit, and we’d only seen him wearing his s4 suit at that point. There also was an appearance of child Talia al Ghul in 1x09 before she appeared as an adult in Arrow 5x10. They’ve also claimed that Smoak Tech is going to be a thing but in this timeline Ray never returned, so Felicity probably had it built adopt Palmer Tech. Now she doesn’t have Palmer Tech so where would she even start? Unless it's a memorial?
Sorry but I really think there is something going on. When I watched the trailer I was fully expecting it to be loaded with present day Felicity scenes yet not a single one and a new element that brings several new questions regarding her whereabouts. If she really isn’t going anywhere and all this Olicity wedding bullshit is actually true then why not just feature at least one scene with the apparent safest character in the Arrowverse since everybody is expecting her to survive anyway? Or of course this is just them trolling like I’ve been saying. What is their motive you ask well the very fact that they’ve been very vocal about Olicity in the past so if Felicity is going to die they kinda have to keep being vocal. If they start dodging Felicity related questions then people are gonna be asking questions and doubting her survival, thus making her as fair game as the others. Again I think this makes her the perfect choice of victim.
However there is a general assumption that Samantha is going to die which I don't deny because I'm pretty sure you can actually see her dead body near the end of the trailer and the way that William is talking to Oliver, the fact that he seems to be with Oliver in Star City and not with his mother, all seems to confirm this fact. However Felicity is also missing and I did hear a rumor a while back that two characters may get killed so what I think it quite possible, is that Felicity and Samantha are both dead. Now Oliver will take to take William in and help him deal with his grief while coping with his own, and being the father William needs him to be could be how he copes with Felicity's death. Remember all of Adrian's lines? "You infect the lives of everyone you touch", "You're one loss away from getting destroyed" and "It's gonna be lonely, without mom and Felicity". All of this sounds like it's all but confirmed. Also even his "You kill me you'll be killing yourself" lines was half-true as he intended for Oliver to kill him and in doing so get everybody killed on Lian Yu. While Adrian ended up killing himself the same end result still happened.