The complicated, money-centric nature of filmmaking means that many more movies are announced, promised and “confirmed” than will ever actually go before cameras.
No matter how much a movie might seem like a great idea that’ll print hundreds of millions of dollars for a studio, there’s always some boring administrative reason that it won’t happen, not to mention “creative differences” or infuriating scheduling difficulties.
That’s to say nothing of the other side of the equation: announced movies that are, to be kind, rather “optimistic” propositions, and simply have no chance of actually scrambling together the cash to get made. Either through a lack of studio faith or the greater financial demands of the stars involved, they’re not happening.
If even one or two of these films actually get made, it’d be a huge shock, either because they’re risky and financially ill-advised projects, or have been caught up in red tape so long it’s hard to see things ever changing. It’d be nice to be wrong in a few cases, but you really shouldn’t get your hopes up…