Googling "Ioannadis 10000" gets you plenty of discussion within links on the first page.

They weren't in the medical literature. The 10k prediction was in STAT news (https://www.statnews.com/2020/03/17/a-fiasco-in-the-making-a...) (note: it wasn't a hard prediction, but he seems to treat it as the best estimate based on the data at the time). The 40K prediction was quoted in the Washington Post (https://www.washingtonpost.com/opinions/without-mass-testing...). There's a good summary with additional links, quotes, and commentary here: https://sciencebasedmedicine.org/10000-deaths/

Thank you