I believe this "teaser" per se for 2018 could be one-shots or a special anniversary project, possibly in the same vein as the Wildstorm Anniversary Hardcover coming out, which features new material and short stories from the creators back in the day. I can't imagine an Invisibles sequel; however, I never thought Lucifer would have a second series (which I did love btw, although by no means was it needed or anywhere as good as Carey's masterpiece). I really hope their is new Sandman material. Again, maybe this could be Gaiman writing that Delirium story he said he had on the back burner.