https://screenrant.com/roseanne-original-dan-death-retcon-revival-conners-how-explained/

In an infamous twist, Roseanne's original series finale killed off John Goodman's Dan. How did the season 10 revival and The Conners bring him back?

It turns out that Roseanne's writing was just writing lol. In the reboot they were thumbing through Roseanne's book and Dan remarks, "You killed off the best character!" So basically Roseanne was writing ABOUT her writing lol. It get confusing, I'm not sure how much from the original series is canon to the reboot...... I'm guessing most everything aside from season 9