Dypatome

Would take far too long to even begin some arcs, in addition how little Game Freak would gain from releasing an anime from a 2-decade year old manga series. Generations works as an anime adaptation comprising the story of every game from gen 1-6 because it hyped up 20 years of Pokemon in tandem with building the release of gen 7. For them to replace the current story, which by the way XYZ & Sun and Moon anime are wholly different in quality than the anime for gen 1-5 (Most especially the shit Best Wishes season), with an entire storyline that absolutely needs every arc to be read to make sense of, they would need to overhaul the franchise as a whole for it to be anywhere near appropriate, much less necessary, to execute. Sorry for the wordy rant but I'm tired of this question in particular. Besides, who knows how much Kusaka and Yamamoto would benefit themselves from having their manga adapted considering the shady nature of the anime industry.