Sad part is they won't get fucked because they can produce the underlying asset. If it costs them like $60 a barrel to pump (which would be very high, most oil can be produced for far less than that) then they're still making $40 of profit. Their only "loss" is the opportunity cost of making even more profit had they not sold these futures contracts.
I don't think it means oil majors think it'll end any time soon, they're just banking so locked in long term profits now to smooth out any price volatility in the months ahead. There's little downside for them.
I have to imagine Fujimoto wanted out of his contract or whatever, was kind of bored with Chainsaw Man, and totally burnt out from weekly releases. It wasn't a terrible ending, just not fleshed out and insanely quick. We were knee deep in the shit just two chapters ago, and then all of that is just gone and it's like "yeah it's over." Thematically it makes sense, so it's not awful or anything, just rather sad that it all just ends so quickly and there's little permanence or growth.