I am certain that Shouji wrote in his new years post in his diary on his website, that they were preparing the roughdrafts for Chp 31! That was either new year 2014 or 2015!
I am sure I read that, because i was really into it back than and read his diarys and saw the number 31! Google translate and boom it said something along the lines of "roughdrafts 31 preparing soon".
Seems like Daisuke never recovered from his health issue. He did a 2 volume novel in like 2015?, but I think he did that to see if he could still do it with is damaged health, keeping up with deadlines and stuff.
Well I respect their decision to not continue after Daisukes death! BUT Dragon Age should have said much earlier that its done and not keep fans in the dark for years! Even when he was alive a little "HOTD can not go on, because Daisuke is not fit" or something like this.
Damn at one point I thought Triage X was set in the HOTD, when the "zombies outbreak" happend in TX, somewhere around Vol11-13. I was like damn do they intend to finish HOTD of through TX? Explain the virus and in the end battle make the cast show up. A crossover sort of thing.