I thought Deng's principles were the foundation for modern China's economic policy? Is this not true?
"After Chairman Mao Zedong's death in 1976, Deng gradually rose to power and led China through a series of far-reaching market-economy reforms, which earned him the reputation as the "Architect of Modern China"." [0]
Attributing reduction in poverty rates primarily to Xi doesn't make much sense given the historical trends. See the world bank info[1] for a sense of the long term decline(1990-2016).