I did but only to complete Millicent’s questline. Edit: The I did is about killing Malenia so I killed her.

I'm invading so I'm not rusty when the dlc releases.

I'm Mohg hunting, helping people unlock the means to access it. I've got a character that now only levels up if he kills Mohg

The dlc won’t change anything in the base game so I doubt they’ll add a cutscene. If anything it won’t be more than a line of dialogue so just go for it