Zip. Zero. Nada. The DC Rebirth #1.
It's tangentially touched on in Detective Comics withand a couple of others, but nothing is specifically addressing Dr. Manhattan. I believe Titans is supposed to be the book that carries that torch, but it's only disjointed references to "being watched" and having years stolen.Oz
This won't be addressed until some Johns event in the undisclosed future. Hell, Batman knows there are three Jokers running around Gotham and has chosen to ignore that as the world's greatest Detective. The whole thing was a Johns cocktease that has affected nothing in Rebirth. Some relationships are back, Wally is back, that's it.
Thanks for the info. That sucks. I was quite interested in that whole plot