I agree with what you said, Valverde is a very useful player for Madrid and there is no way Madrid will give up one of their best assets to bring Mbappe because they also want a very high price for Mbappe.
Now maybe we'll just wait to see how things go with Mbappe and PSG first because this also determines if in the end Mbappe still remains with his wishes then this will allow him to be released just like that with the 250 million + that was always discussed before. Everything depends on Mbappe because if he stays with his previous statement then his drama about Madrid will continue to lengthen but if he decides to extend the contract then this will be finished but on the other hand it is a loss for Mbappe because he will still be the same as before without any improvement at PSG.
PSG are still trying to keep Mbappe even though they know he has rejected the offer of a contract extension, the price PSG is asking for is really unreasonable for a player whose contract has one year left. The Mbappe transfer drama was very complicated, Real Madrid kept trying to bring Mbappe to the Bernabeu, while PSG seemed not ready to part with Mbappe.
PSG hopes that the arrival of Luis Enrique can change Mbappe's attitude, he is a much needed player on the PSG front line to start a new story with an experienced coach in the Champions League. Luis Enrique will try to convince Mbappe with a new project to make PSG a European champion, Enrique will make a big breakthrough at the beginning of his leadership at PSG. If Real Madrid withdraws from hunting for Mbappe due to a too high price and Mbappe sticks to his stance, PSG must be ready to let Mbappe go for free next season.