Vincius is an incredible player, smart, clinical, and decisive. Real Madrid wont want to lose a precious gem at his stage they are trying to rebuild the team to what it was in the past. We saw how they lost the La Liga to Barcelona, lost 4 matches against Barcelona and also were eliminated in the Club World Cup by PSG. That alone is enough reason why Xavi Alonso can never let Vinicius go, so far he is one of the remarkable and experienced player in the squad, so until the squad sits well with him, Vinicius still remains.
Real Madrid value Vini's contribution to the team, and they really want to keep him, but if he leaves, it won't be Real Madrid's doing. AFAIK, he has been handed a new contract, but he's asking for a higher salary. I don't know the details of the new contract, but I'm guessing it's more than what he was earning, and if they cannot reach an agreement, Real Madrid will have no other choice than to sell him. He has already been given a deadline to sign, or he will be put up for sale.