Oatly AB intends to have a 2021 initial public offering that could draw $1 billion, CNBC's Leslie Picker reports, citing sources familiar. The company, which is backed by Blackstone (BX), Oprah Winfrey, and Natalie Portman, has tapped Morgan Stanley (NYSE:MS), JPMorgan Chase & Co. (NYSE:JPM), and Credit Suisse (CS) to manage the IPO.