We don't know when Bayonetta 3 is coming out yet, but the American Video Game Rating Board has just raised the rating for that game. Unsurprisingly, Bayonetta 3 has been rated as a game suitable for ages 17 and up. If you're wondering how 17 and not 18 works, that's how it works in the US where M-Mature refers to the age of 17.
In any case, Bayonetta 3 got that designation because of the violence, blood, partial nudity, swearing, and… microtransactions. For nudity and violence, it's nothing strange, because the previous two games from the series carried the same label. For microtransactions, we are not yet completely clear about what will be sold - it is possible that they will be only cosmetic (eg additional costumes for the title character), or items that affect the gameplay.
Bayonetta 3 should be one of Nintendo's biggest exclusives this fall, but as we already wrote - its specific release date is still unknown. We first got a fair look at the game at the beginning of this year, but it's been in development for five years.