if Real Madrid sells Vinicius, I'm very confident their performance will be poor, perhaps even worse than last season. So, I don't think Real Madrid should be tempted by big offers from Saudi Arabian League teams. They should prioritize their performance and the goals they want to achieve next season. Moreover, they've just brought in a new coach, so to keep him busy developing a solid strategy, key players like Vinicius shouldn't be sold. However, I'm confident Real Madrid won't sell Vinicius, especially as we know he wants to stay at Real Madrid for now. So, given this, Real Madrid will definitely keep Vinicius.
I disagree, that only depends who they will replace him with, and how they will play. What they need right now is just players that they could play to fit Xabi's system. This is why the best thing for them is to have a plan before they do something like this, even if they do it.
The best thing that they could do, would be just selling Vini, and finding someone who can fit better, and sell Rodrygo too while at it, if they can do this, sell these two, they can make easily 300 million income. With that amount of money, we could see them do a lot better, because with that kind of money, they could get some super players and could have something much better. Focus on that, and you could get a great return and they could be a better team. But if they sell, and get some shitty players, then it would suck.