LLMs are going to make meeting deadlines more obtainable (or just move the goal post on deadlines so you still have to do more while working the same hours).
This stuff is going to hit for indie devs, one or two man shows, working part time with no budget. The first one to get a smash hit, which will be because of the game play dynamic not the content, with 100% AI coding and be the proof of concept that will change the whole game. Its great for indie devs. No so great for AAA who will actually have to start having original ideas, not just "What if we make another FPS that copies X and Y"
After those indie devs start to make some cash they will spend it on original art. Not for moral reasons, but as you say, for originality, which even for humans is difficult these days.
AI doomers are looking at this wrong. Its the democratization of the game industry from the AAA monopolies. Platforms like Steam have made this possible.