Steve Jennings/GettyDiane Greene, CEO of Google CloudIn November, Google Cloud's Diane Greene announced she was stepping down as CEO.This made a splash in the news, as Greene was hired at Google Cloud to run its enterprise operation and has strong enterprise chops, as a co-founder of VMware. In January, former Oracle executive Thomas Kurian will replace Greene. Kurian, who had been at Oracle for 22 years, was the company's president of product development, where he led its cloud-computing efforts. He resigned in September after clashing with Oracle founder and executive chairman Larry Ellison.Greene said she hadn't planned to stay in her position as Google Cloud's CEO for long. Still, now that she's leaving, and a long-time Oracle executive is moving over to Google, major shifts in the cloud wars may be coming.At Amazon's cloud business's annual conference, AWS re:Invent, we spoke with six enterprise startup executives in the industry on their thoughts on this leadership shakeup. Here's what they have to say about what it means for Google and for the cloud computing industry.Get the latest Google stock price here.