Kimetsu doesn't really "need" any boosts or anything, it basically already broke OP's Oricon year record, because it still has 3 volumes that will get released this fiscal year, that without a doubt will sell 2million each, plus demand hasn't been met yet for the backlog (I know I said plenty of times that maybe demand had been met, I was wrong).
Congrats to Gotouge-sensei.
Kimetsu's success has me wondering though..
Has there ever been another series that sold so "explosively" in the history of manga?
I know of Dr.Slump's boost from the volume where its anime adaptation started, but it's not the same, in the case of Kimetsu there was a 20ish times boost in sales (Volumes were selling 130k-ish pre anime adaptation, now they are close to 2.5million, and might even reach 3million).
When you think about it, KnY might be the only contending manga to break One Piece's fasting 100 million volumes, other contestants were too slow (e.g. Attack On titan being a monthly release) or didn't reach the number of volumes required assuming each volume sold around 2.5 million (e.g. Yu Yu Hakusho being only 19 volumes long and I don't think YYH really got to 2.5 million per volume at the time it was first released, or Slam Dunk being only 31 volumes long).
The other series that may have sold at a faster pace than One Piece and had 40+ volumes was Dragon Ball but I think it having more chapters per volume kinda handicapped Dragon Ball because it needed 15 or so chapters per volume (So basically Dragon Ball was released on a slower pace than One Piece's volumes.)
Outside Jump there's Touch that reportedly sold 100 million copies with only 25 volumes...
And this Wikipedia entry has Black Jack at 176million copies sold with 25 volumes..
I have seen too many different figure sales for Tezuka titles,
I just think Black Jack didn't sell nearly that many volumes, for example this article by Deadline has it at 50million volumes... Sure it's an article from 2012 but I don't think BJ could have sold 125million+ copies in the span of 8 years lol
But Touch.. Touch would have perhaps sold faster than One Piece if it hadn't finished at 25 volumes.
So.. Yeah, if KnY doesn't end soon as some of you have suggested, then the next record to take from One Piece would be its "Fastest manga to achieve 100 million copies" record which One Piece achieved on February 2005 with the release of volume 36.