This is about Milton reading and annotating the published collection of Shakespeare's plays, not Milton meeting Shakespeare in person. It doesn't have any bearing on the debate over Shakespeare's identity.

The title is a little misleading.

Milton would have been not yet eight years old when Shakespeare died, to boot, so I'm not sure a physical meeting would have meant much to him.

People would be talking about him/her during that time, so I think their observation would have been very relevant had they made one about the identity.

Very few historians doubt Shakespeare's identity. Wikipedia doesn't even categorize him as "people's whose existence is disputed."

You're right, I shouldn't have even called it a debate.