Clem-6X06 is part of the Slade 2 parter so I wouldn't have my hopes too high for Olicity there.
Japril-She never said Dinah's new LI was already on the show. You're confusing her saying we've already seen Vigilante on the show.
We started with the concept of ‘wouldn’t it be really funny if Barry goes for a bachelor party with the guys, and Iris goes for a bachelorette party with the girls, and the guys end up having the worst night ever and the girls end up saving the city’?” Kreisberg says about the development of the episode. “That was where the episode started from, and that’s where it ended up.
Some additional info about The Flash 4x05: Girls Night Out (Guest Starring Emily Bett Rickards) from Flash Executive Producer Andrew Kreisberg
http://comicbook.com/dc/2017/10/30/f...er-no-costume/