Jude Bellingham place in the madrid team is not in contest. When Ancelotti moved him close to goal was because of inavailability of a striker and injury of Vini Junior. When Vinicius Junior came back, he reverted to playing Bellingham in his normal position
There will not be position issues in Real Madrid, the problem will be on supremecy, who will the team be built around. It will be unfair if they deny Vinicius his time to reign and favour Mbappe.
To hold that role, in my opinion, Real Madrid still has players who can hold it, one of which is Luca Modric. He still has the chance to stay at Real Madrid next season, although he will make a decision after EURO. But it does give hope that he may still be in the Real Madrid squad next season.
In my opinion, giving that role to Mbappe is too early, he is a player who just joined Real Madrid at the end of this season, and I think there are still many players who can play that role.
In my opinion, Vinicius can't hold that role yet, so Ancelotti has to choose another player, it could be in defense or something else. However, it is better for them to prioritize the interests of the team, because when they can mature with each other or understand their respective roles, then they will not depend on the instructions of just one player, they will be able to be more flexible in doing so.