This is good the trademark failed. It might have been more of a defensive move rather than trying to lock up the term for OpenAI's exclusive use. Although, I'm sure they would have been happy if it succeeded.

Question for a lawyer, but in my experience it's common for companies to file trademarks with the expectation they'll lose. This creates a precedence for others trying to file similar trademarks and clears the way for the company to continue using the non-trademarked term without fear of future lawsuit.