That does not seem accurate. SteamSpy estimates 16.11m units sold for HL at the time of this posting while BG3 has an estimated 28.67m units sold. But I guess consoles are probably a massive chunk that I can't see. But again, the poster on twitter says they have 28 million HL sales, it'd be hard to believe steam outsold all the consoles with those number estimatins for HL.
Circana’s report does not include download sales from some publishers, including Nintendo, however. This means Tears of the Kingdom’s place on the list, for example, would be higher if all sales were included.