I think it would be a great, fun little addition if Chromie had some extra dialogue. Obviously, don't change her existing dialogue or the quests she's a part of, but just add an extra option. Something that addresses/vaguely hints at her knowing Classic is an alternate universe/timeline. After all, the announcement trailer is of her using a temporal discombobulator to rewind time, so it would make sense that she's the only one who knows.
It could be something like an extra dialogue option that says "What aren't you telling me?". to which she replies with one of a few random lines, like...
"Nothing! I definitely can't tell you about Neltharion sundering the world! Er, i mean...forget you heard that!"
"Have you met the knights of the Ebon Blade yet? I can't remember if they're around at this point."
"So...does this technically mean Ragnaros gets summoned a THIRD time?"
"Hey, thanks for stopping my death! Wait...that wasn't you. That was ANOTHER you...i think..."
Or maybe, blizz could just give us an option to thank her since, after all, she's the reason we get this second chance. Thanks, Chromie.
I think that's a good idea too, but they should also add dungeon finder.
Humor is always welcome!
inb4 Threkuul edits the post so that it's calling for LFR, LFG and cross realm raiding