After Jesus' ascension,
He received the information from the Father
that the disciples asked for.
And before the end of the first century,
while at least one of the disciples was still living,
John,
Jesus sent an angel messenger to impart to him
and through him to the churches,
the information that is "unveiled"
in the Book of Revelation.

...........The canon of Scripture would not be complete without the message from Jesus to His Church after His return to Heaven.