Interesting! I initially thought the beautiful woman might be Shadowheart but that makes less sense now that she’s not always found by the temple doors.
The elf heading north I thought might be Astarion, unless a gender is mentioned? But then I also thought the pod you find near him was his and he’d come down in it and broken out afterwards, in which case he wouldn’t have been on the beach.
Minthara we see watching the crash with Ragzlin from the Shattered Sanctum so it’s not clear she’d have time to get down to the beach and wander around. Because the fisher is attacked by intellect devourers while being distracted by the beautiful woman, he must have seen her post crash. Though I guess it’s not clear how long we’re unconscious for after the fall, so I suppose it’s possible she nipped down to investigate.
At the moment, I think it might make more sense if it’s someone (or someones, if the woman and the elf are different people) we’ve not met yet, but also suspect that, as this is dialogue that’s been there from the start - I think, that it might just reflect an earlier, now superseded version of events Larian had in mind that will be tidied up and changed for the full release.