Okay, I searched a little bit. So what I found out was that the author had some disagreement with their previous publisher's company regarding payment or something (not very sure), but after that, the author stopped making new chapters.
It seems like the company had all the intellectual rights for "Black Haze," and the author tried to take the rights back, but the company refused. The author was also in contract with the company, so they were just waiting for it to expire. (It is just what I found on the Internet, so I don't know how much it is accurate)
Anyway, I'm so glad that "Black Haze" has returned. And I am definitely enjoying and loving the new and improved art style. I'm just hoping and praying that it never goes back on hiatus ever again.
I saw the last chapter of it and it ruined everything for me.
Sorry, but I think I will not be able to continue it.(ToT)