Kimetsu Producer Takahashi Yuma had an interview with nikkei(He won marketer of the year) with some information on how they handled Kimetsu Marketing/Production
1- Takahashi is a fan of the manga so shortly after the series started, he approached Shueisha to adapt it into anime and he decided for Ufotable to adapt because he felt it fits them(Battle scenes, mostly takes place at night etc) and he has been working with them for more than 10 years
2- The depiction of blood was important so they decided to air it in a late night slot to not censor anything
3- While most late night anime airs in 5-6 channels, they contacted more than 20 channels to air it and more than 20 streaming services to have the anime so it could reach a lot of audience.
4- Ufotable asked for the first episode to air without commercials
5- They wanted the opening song to be heavily associated with the show so they decided that it won't change during the 26 episodes
The full interview is
here but you need to register to read it.
