Shibuya arc is the peak of JJK. Current arc had ups and downs
Yeah, some of the fights were a slog to get through while the following lore chapters were more exciting even with less action.
If it really ends up being true, 40ish chapters (counting in Gege's breaks here)
could wrap up the main plotlines but it would come at the cost of a lot of them feeling rushed.
For example, a fight against Sukuna has to happen but if it is wrapped up in 3 - 4 chapters or less, it would be a huge letdown. Especially if (or because) a lot of plotlines would need to be connected to that fight and its resolution in order to finish everything in a year.
Personally, the worst thing about this news is that every subsequent chapter will be looked at through the scope of "hmm how rushed does this feel". Because we have a timeline in mind.