It could just be a force vision. Imagine if this shot had been in the ESB trailer.
Which means that Luke sees himself in Vader. The Darth Rey shot of the new trailer is featuring a look and a weapon Rey has no reason to imagine (ie if it was a Dagobah sequence, she would picture herself as Ren, not as something new).
She saw places in her TFA Force vision she’d never been to let alone seen before, why is this different? I don’t think the rules on Force visions are written on stone tablets anywhere.