With Roseanne coming back, the writers obviously have to deal with the sticky issue of how a lot of "canon" was erased by chalking it up to having been part of Roseanne's writing in the final season of the original. The biggest one is Dan's death. In the original series finale, Dan surviving his heart attack is revealed to be part of Roseanne's writing as a way to cope with the fact that he actually died.
In the reboot — spoiler alert — Dan is not dead. And the show makes a couple of wink-wink references to it.