I guess designers will be able to do user research and rapid prototyping with tools that are provided to them and then once they have a good product it will be passed to an implementation team to get implemented? Obviously once that's done it's released to the customer and there will be no need to ever change the design because by this point it is infallible.
One of the issues I can see here is that the design prototype will need to be kept in sync with the implementation, and designers will have to rely on prototypes being an accurate prediction of user's behaviour.
I do think the "interesting/creative work" baseline will probably get worse for many software engineers but I hope this takes 50+ years. I guess creativity and innovation is a scary thing for people and it's probably only a matter of time before the bean counters try to optimise/regulate and ultimately squash it. (And I believe they will for the non-creative have very little clue on where ideas come from and will squeeze until the golden goose stops producing eggs.)
When/if this happens I don't plan to be working. It would be unbearable to do non-creative work. I'd exit somewhere that I could keep my dignity and write poetry or programming for people that I met without the meddling of inward-facing fools.