If a game adds or changes content outside of extra add-ons like DLC (such as a free update) does that content have to be reviewed by ratings boards and risk changing the rating of the game?

I was talking about bg3 and how a certain part could be changed to be much darker, and it occurred to me that it possibly could affect the rating of the game if they did (being vague purposely to avoid spoilers). But then I wondered "do things like that even have to be reviewed by the rating boards?" Because Larian has made a lot of changes like that to the game and I imagine it would be pretty ludicrous to have each and every one be reviewed to see if it fits within the current ESRB and PEGI ratings of the game.