The updated number for the total lifetime sales of the Metal Gear series puts it at 58.3 million, as of the end of March 2022. That means 300,000 Metal Gear games were sold between December 2021 and March 2022. Looking back at the whole year, the franchise sold 1.2 million between March 2021 and March 2022.
On November 8 of last year Konami removed several Metal Gear games from digital storefronts such as PlayStation Network and the Nintendo e-Shop, because of licensing issues. As of now, the games still are missing, with no update from Konami. However, in their official statement they did say they were working on making them available again in the future.
Source: Konami Official Website