But a short time after this statement news websites started to write like Mbappe has already agreed with Real Madrid.

Do you think this can be real? Honestly, I don't think so.
Mbappe will just try to do his best to help PSG win the Champions League title this season. The result of this effort would surely be effective on his final decision on the transfer topic.

Mbappe position is quite confusing, on the other hand he wants to be in Madrid immediately but he also has an agreement to finish this season with PSG. Madrid actually opened the door too much for Mbappe, who had rejected offers many times in the past. Now Madrid needs to show a little ego that they are a big club that Mbappe cannot play with. Even though I know Florentino desire for Mbappe is very clear, it is still important to maintain Madrid good name. Let Mbappe finish with his own decisions because at PSG I see there is a kind of shackles that he can't get rid of yet.
Manchester City which was missing their few key players now having good time and things can give them good advantage with first leg match is also still have nearly one month which mean they will be in better shape and surely going to have good booster for another double which is not easy this time.
You are right, Manchester City has quite the advantage after the break in the round of 16. Because they now have the opportunity to improve their squad and ensure that each of their key players returns in top condition and free from injury. This is also another starting point for Manchester City to achieve victory more quickly. Not only in the UCL, because in the Domestic League the targets are quite tough requiring Pep Guardiola to be more careful with the tight player rotation schedule that needs to be carried out continuously to avoid undesirable things.