I suspect they are doing this since they don't want the Northeast to become depopulated and everyone to migrate to the Pearl River/Yangtze River Deltas. Still, I don't think Xiong'an will be "Shenzhen 2.0" or anywhere successful; Shenzhen is successful because of its sheer dominance in hardware manufacturing, along with the rest of the entire PRD (which alone is responsible for some ~40% of the world's assembled phones, and 90% of all global electronic components) hence why its called the global "Silicon Valley for hardware". I think they want Xiong'an to be more of a software base actually reminiscent to America Silicon Valley (i.e. the globe's software capital). But even if Xiong'an isn't as successful, as long as it provides opportunities for young people in the Northeast so it doesn't become more and more depopulated, that I think is a win in the eyes of the Politburo.
Shenzhen isn't just a hardware hub though, its two biggest companies Tencent and Huawei are both major software companies. Huawei has been constantly ranked China's #1 software company.
Beijing has the deepest talent pool in China with its elite education and research institutions. It has China's two biggest unicorns Bytedance and Didi. Baidu, Meituan and Xiaomi are also headquartered there.
Xiongan will NOT get the cream of the crop from Beijing. Expect back offices of SOE giants to move from Beijing to Xiongan (but headquarters will stay in Beijing). Elite institutions may open second campuses in Xiongan. Some research institutions and think tanks may move. Don't expect central government offices to move though. Won't happen.
I think one key to Xiongan's success is connectivity with Haidian, Beijing's existing high tech center. There should be a high speed link (maglev?) between Haidian and Daxing Airport which is between Beijing and Xiongan. Otherwise Xiongan will suffer from being located on the other side of Beijing from Haidian (you don't want to cross Beijing without a direct connection!).