It does, deadlines are terrible there, not only that but some places are even worse like like author of "How to Protect Heroine's Older Brother" had miscarriage because they pressured her during pregnancy...The brat's commentary about authors not being able to choose their deadlines at all feels... wrong. Does it really work like that in Japan? Or is this just misappropriated from the actual author's own experience with manga that goes out in periodicals?
(Honestly if Nee-san actually did put that much pressure on a 15-year-old author I wonder if you wouldn't be running up against some labour laws. That's besides the point though, artistic license and whatnot.)