Is “After abdicating, he was poisoned to death by Cao Pi” true?

The Records of the Three Kingdoms, Book of Wei, Annals of Emperor Wen records that after Emperor Xian abdicated, he was enfeoffed as Duke of Shanyang, enjoyed the rites and music of a Son of Heaven, and died of natural illness in the second year of the Qinglong era, ending well. (Original text: 「青龙中，山阳公薨，汉主也。肃上疏曰：“昔唐禅虞，虞禅夏，皆终三年之丧，然后践天子之尊。”」——Source: data/raw/sanguozhi/魏书·锺繇华歆王朗传.txt)