Having AI be able to flesh out story boards will certainly help. Even better if it 'learns' from the classic story telling texts and forces bad writers to adhere to the basic principles for telling a narrative, establishing character, and driving a plot. AI will probably help with continuity, adjusting script changes on the fly (changing a characters name and it changes everywhere, or maybe even helping flow when scenes are shuffled around and it can detect when key information wasn't placed where it should be).
AI will DEFINITELY be used for quick pick up shots or replacing an actors expression with another. Reduce the number of takes required for those mid level projects that can afford the tech but not the 50 takes necessary to get the "perfect scene". I bet we will even see a shift towards actors who are, for whatever reason, 'easier' for AI to replicate, either due to a distinct voice, mannerisms, or facial features that make them easier to fake without the audience seeing the flaws.
I bet there will be hundreds of folks paid to be "AI models" with their body, movements, and speech records and then used ad nausem as extras with no additional compensation to the human model. Basically the "Wilhelm scream" of the AI generation.