Why is this relevant now? Well, at least one current Switch game and a potential re-release is probably affected.
A new European ratings board ruling has gone into effect that would have a major effect on current and potential future Switch releases.
The PEGI board has determined that references to gambling would result in an automatic 18+ rating: according to reports, this actually began in early 2021. A recent example as spotted by AskAboutGames has found that the game Overboard!, released on 2 June with a 12+ rating for "mild violence, suggestive themes, use of alcohol" is now 18+ for "simulated gambling" due to a game of blackjack. In North America, Overboard has a T rating for "Suggestive Themes, Language, Use of Alcohol, Mild Violence, Simulated Gambling".
The main effect of this would be for the Pokemon series: the 2016-18 Virtual Console releases on 3DS were rated 12+ for gambling in Europe due to the Game Corner's slot machines. Although the ratings have not changed for these old releases, every new Pokemon release in Europe since Heart Gold and Soul Silver (2010) have either removed the slot machines in favor of games of skill or removed the function altogether. Brilliant Diamond and Shining Pearl have reportedly replaced the Game Corner with the player character's clothing store,
but a straight release of Pokemon Red/Blue/Yellow on Switch would either require the Game Corner to be removed or the 18+ rating applied. (See update below)
UPDATE 3 September: According to PEGI, re-releases of games that do not alter the "experience" significantly would maintain the 12+ rather than the 18+ rating. In the Pokemon example above, an HD remake of Pokemon Red/Blue would have to remove the Game Corner but a re-release of the originals would not. (The games were removed from the Game Corner in 2018's Pokemon Let's Go Pikachu/Eevee which brought the European rating to 7+.)