Editor’s note (July 10th): Fidji Simo has stepped down from her full-time role at OpenAI for health reasons.Game Pass, which was meant to have 77m members this year, has fewer than 30m. (Reuters)IT IS NOT yet the PayPal mafia, but the Instacart matriarchy is making its mark. Not long after Fidji Simo, ex-head of the online grocery store, became Sam Altman’s product-focused sidekick at OpenAI, Asha Sharma, Instacart’s former chief operating officer, became Satya Nadella’s Ms Fix-it at Microsoft Gaming. Groceries are a tricky, low-margin business. So is Xbox—and Ms Sharma has wasted no time in getting to work. On…