With all that success it makes it all the more odd she would rip the heart of the story right out of the manga.Yep, pretty much, and the numbers go against it.
Vol 9 announced 600K copies total, and Vol 11 announced 750K:
That's 150K over two vols (9 + 10), which isn't, like, ultra popular, but it's still a healthy number that no publisher would axe a series over, much less Kodansha lmao (yes, I'm still, once again, angry about ヤンキーJKの異常な愛情). Obviously, some of that could've come from older volumes continuing to sell, but those are usually the minority.
On top of that, this series loves to GLOAT every time it hits #1 on one of the digital big boys, which is exactly what they did with vol 12's Obi, which was all about how they hit #1 on the DMM daily manga ranking (on top of the live-action streaming + some collab thingie).
So at the very least, ranking highly on digital platforms seems to be important for this series.
BUT, bad blood between a publisher and a mangaka can take many forms, so you can never completely rule it out.
Now if this was guilty circle I could believe the publisher told them to wrap it up since it's just repeating itself over and over again.