On the upside, they don't really get into who, what, where, when, why. All we saw was a few snippets of the story end. I think us knowing what happened fills in the blanks for us, so it feels more spoilerish. Some shit happened, the WoL (us as a whole) ends up in catacombs (lol thats what it looks liek if you remove what, when, why and where they are), Lalafels coming across evil (we kinda knew this about the syndicate from ages ago - but fully new people wouldn't know who that was and why he has a creepy-ass smirk) and an old man in a cell (Sorry, Raubhan!.... but dayum you need a haircut).
Take out the whos, the wheres and the whats and you have just 'some midget lady with wine, conflict, snow and dragons'.
Those that's never played FFXIV, like you mentioned won't know one from another. THey don't know the Coerthas conflict, the don't know MIdgardsormer's reasonings behind the dragons, they don't know about the Holy See and the power grabs.
If I just randomly watched an episode of some anime or show in the middle of no where with no context, I wouldn't know the whole story.
Even if they showed a huge chunk of the main story end, thats nowhere near the complete story from 2.0-2.55
If you were to take the pieces of the trailer and show it to someone who knew nothing of the story (as you mentioned the non-player friends), it's easy to come up with their own conclusions based on looks alone. For ex, Raubahn could look like some terribly strong criminal that was locked up for ages after going on a killing spree - and then eluding to his breaking loose. It could be the farthest from the truth, but I'm trying to use an example of what I mean from my paragraph above.
For us and the current players, it's a spoiler. We know whats going on.
For new players, it can only offer intrigue. Why are dragons attacking? Who are those Dragoons? What is this snowy place, is it a temple? What is that giant castle place? Who is that strong looking fella, is he a criminal (ref to the banquet scene + prison scene... and Rauhbahn just looks intimidating)? Will he break loose? Why are they being chased? What did the lalafel do? Is he evil (okay, that one's true, but they don't know that)? WHo are all these people??
(and other examplery concepts, but I'd have to watch it again. I'd only been half paying attention the first time I saw it over the weekend).
I think the only thing that would be a turn off for new players in seeing this trailer is the singer lady NOT hitting that high note -.- *Covers ears at the high pitch*