Guardiola has contract until 2025 so he will be there for sure until then and also I don't think he plans to move yet to another league just yet. Also the message he *jokingly* sent to Real Madrid can also be slightly determined as him focusing on next CL from now. I am sure board are happy with what Pep has achieved here and will do everything in their hands to meet his demands so there is no problem there and also I don't see any discontent in the mind of Guardiola yet to make him move to a new league. I would say likely chances is for Guardiola to stay even after 2025 but that is what as things stands as of now.
Manchester City will not let Pep Guardiola leaves their club if he does not want to leave. They know that he did great things to improve quality of Manchester City and is able to continue it in future. Pep Guardiola is like Zidane and they are smart to know when their players hit limits and start their career downhills. I believe Pep Guardiola will not stay in Manchester City more than two more seasons but he will try to win one or two more Champions League with those players if possible.
Manchester City deserve to win a first Champions League for their club after last few good seasons. Even in the final, they need luckiness to win but if looking at last few years, they really deserve to lift the cup after all.