I would say that this post here could almost be the OP for a whole new thread. Those things all happen within the first 10 minutes of the movie, but they sure SOUND like spoilers don’t they? They aren’t, for the same reasons you gave at the start of your post (that I didn’t quote).
Setting aside the question of if something that is 200 years old and has been made into dozens of film adaptations and the most popular Broadway play of all time can even have spoilers, setting aside that the whole concept of a spoiler has morphed into something totally strange in the last 10 years or so, shouldn’t you allow that people who actually are familiar with the work know better than you what is important to keep secret and what isn’t?
How Valjean dies is sort of important, THAT he dies is pretty much a given based on the setup of the story. It sets out to tell his whole life story, which by definition includes his death. Why Fantine dies and the details surrounding her death…MAYBE maybe should be hidden, but her death is more or less the inciting incident for the plot. It’s like giving away that Dorothy accidentally kills the wicked witch of the East when she lands in OZ. Maybe it sounds like a spoiler if you don’t know the work, but it really really isn’t, it’s the start of the story. If you haven’t seen OZ, you just have to trust me on that.
Because it’s a set-up, not a reveal or a turning point nor an unknown conclusion (a known conclusion would be a biopic of a person’s whole life, and so, you know they die at the end).
It’s like if the actor playing Superman ‘reveals’ that his character really is an alien and not human. That’s part of the set-up.
Fontine’s death might as well be in the jacket of the book: “…but ValJean’s true redemption comes when he uses his freedom to care for the orphaned child of one of his worker’s whose death he holds himself responsible for.”