Thanks for the chart of Kaguya, really happy it got some boost. I wish it was in WSJ, despite claiming it is a seinen manga, it is shounen level and tame really.
Most recently, two years and 8 months between the end of Eyeshield 21 (June 2009) and the start of Haikyu (February 2012) only had Kuroko as a notable sport series going on, if I'm not mistaken (of course, there were other small sports series attempts during that time like Light Wing, but nothing too notable afaik).
Other "notable ones" (at least a 1+ year run) were Robot x Laserbeam and Kurogane, managing to last around 65-70 chapters. But yeah, Kuroko was their last true success for sports not counting Haikyuu of course.
Doesnt make sense to end HZ until there is a new sports series that has established itself. Surely they would want to keep two sports series going, unless therse been a period of time in JUMP where only one sports series is running for an extended period of time
Like I said it up there, HZ should likely make it out alive of this cancellation round thanks to newbies, but I am certain it will be cancelled in 2 axe rounds (so mid 2019). Gives the author time to wrap, they may start a new sports manga and there you go.
I believe Yuuna is in the biggest danger out of the bottom 3 veterans. Souma still has sales on its side so it will be Bleach 2.0 (on a smaller scale), Zumou still has the anime ongoing and Yuuna is....just Yuuna really. Nothing going for it except the flop anime and falling sales each volume. Falling sales got Robot x Laserbeam cancelled, so will this one.