It's a little bit more specific than that, prompt rewriting is a step they added intentionally to remap prompts. So not exactly trained to make them less about reality, but actually changes your prompt to the image generator to be less about reality
Sheng found an explanation deep within the technical documentation for DALL-E 3, OpenAI’s text-to-image AI model for ChatGPT: An internal language model rewrites or expands user prompts to add more details before images are generated.