Any 4X fan should know about Explorminate. But if you don't follow the podcast regularly, this episode offered a lot of good insight into the design history and philosophy that went into Old World as well as direction going forward:
https://explorminate.co/podcast-interview-with-soren-and-leyla-johnson/
https://explorminate.co/podcast-interview-with-soren-and-leyla-johnson/