Sounds like it was always going to get a proper ending. From the article:

"It was a decision we made three years ago," Heinberg shared about when the call was made to wrap the series with two seasons. Based on his conversation and reporting from EW, Warner Bros. Television had a writers' room in place to chart out where the adaptation could be heading before the first season premiered. Heinberg shared that "lots of different versions of what season 2 could be," were put into play before the decision was made to focus on Sturridge's Dream. "There are some volumes where he just appears in two scenes," Heiberg explained, noting how focusing on Dream's direct story reduced the amount of source material dramatically. "There's so many protagonists in Sandman, but you think of the whole thing as his story."

"It turned out to be about another season's worth of story, without leaving out anybody's favorite moments or scenes. We managed to add a great deal of material, as we did in season 1, and a lot of really fun surprises for fans of the comics who know the entire story. We pulled from a lot of different sources. We took a lot of the single-issue stories and wove them into the fabric of Dream's narrative," Heinberg continued.