I'm not entirely sure it's the best idea to put such a young coach in charge of a team like Real Madrid. The team is strong and with or without him they can succeed, but I think he still lacks the experience to win the Champions League, for example. There are different rumours on the net, and that Vinicius will leave, and that Real will be built around Mbappe from now on, but so far it's all rumours
Nobody is bigger than the club, if Real Madrid appoints Xabi as their manager, they have no choice to accept him as the head coach of the team. Regarding Vinicious, that news is fake, the least Vinicious will do is leave Real Madrid, if you look Real Madrid, you will know the player that's likely to leave and the one that will stay glue to the club like a family business, Vinicious will stay until he get everything he want in Real Madrid and the retire to another club when it's time.
Anceloti said they have found another strategy to use for Real Madrid players, we will see if these players are good enough to move forward to the to of the table or move downward on the table. It's already getting worse with their performance, I hope they get a turnning point.