Unknown? What do you mean?
Mbappe issues already spread anytime since the previous season. Although Real Madrid failed to sign him in the previous transfer window, it doesn't mean that Mbappe has no chance to move to Real Madrid. Moreover, Real Madrid still prioritizes Mbappe as their main target, meanwhile Mbappe still dreams to join Real Madrid. So, public (all people) must understand that Real Madrid has a good chance to sign him.
Mbappe mustn't renew his contract with PSG. If he extends his contract, he may play forever with PSG. I actually don't understand why PSG too relies on Mbappe for their attacking line. I think PSG will be better to sell him and get huge funds, then PSG can buy another top striker for their attacking line. PSG also can lower the salary for the new striker, it is probably lower that Mbappe's salary.
Indeed, previously rumors regarding Real Madrid and Mbappe had been going on since june of the previous year and a lot had happened because there was a drama that made it difficult for Madrid to bring in Mbappe last season and had to wait in the january transfer market but heard the news circulating that Real Madrid had made a pre contract offer to Mbappe but there has been no confirmation of the certainty, but there are also rumors that Mbappe actually wants to join Madrid, just not in january but in june when his contract ends, whereas Real Madrid wants Mbappe to immediately sign a contract before the 16th UCL match begins to win the UCL title again.
but according to what I have read, it looks like Real Madrid will indeed get Mbappe but it won't be this soon because I'm sure there will still be drama happening again because regarding Mbappe move is still a mystery that is difficult to predict.
TBH, I really want to see Mbappe performance at Real Madrid so that he can have a career as a star player and win titles at UCL to make Mbappe name known throughout the world, but however, this is Mbappe decision and all his future is more suited to being at Real Madrid than being at PSG.
and regarding renewing his contract, it doesn't look like it will happen because in the previous transfer an explanation was given that if in last year's transfer Mbappe did not receive a contract extension in June this year Mbappe would leave as a free agent.