OpenAI on Thursday announced a series of changes that will upgrade ChatGPT for both paid and free users.Why it matters: Free AI plans from frontier labs now offer more intelligence than most people will use, while enterprises are still figuring out how to budget for advanced capabilities.Driving the news: OpenAI said it will shift the default model for all users to GPT-5.6 Luna this week. OpenAI says that responses featuring at least one factual error were 62% less common with Luna opposed to th...