serialized manga format as before. no rough drafts left by Miura, but Kouji Mori (supervisor, Holyland mangaka, close friend of Miura) knows the entirety of the plot and they are working off of it. Miura's production studio producing it, will try to write "as not to deviate from Mr. Miura's own words."
I can't say I've been a massive fan of all of Mori's works and some of them go off the rails in the worst way, so I'm tempering my excitement somewhat wrt this announcement