Why did Madara's Gedo Mazou disappear?
It's because he wants to revive the Juubi in complete form.
Minato still has Yin Kurama.
That is why Madara held back from using the Juubi, he still needs to defeat Minato and extract the other half of Kurama before reviving the beast.
Madara will go after Minato.
Therefore, it is inevitable that Madara will fight Minato.