Hebrews 1 tells that he won't because he doesn't need to.
No, Hebrews 1 tells us that God spoke through His son Jesus Christ while Christ was on the earth. I missed the part where it says "never again will God have any prophets on the earth."
God will not only have prophets but he won't do anything without first alerting them:
Amos 3:7
7 Surely the Lord GOD will do nothing, but he revealeth his secret unto his servants the prophets.
Jesus will not return to the earth until there has been a restoration of all things including having prophets on the earth:
Acts 3:20-24
20 And he shall send Jesus Christ, which before was preached unto you:
21 Whom the heaven must receive until the times of restitution of all things, which God hath spoken by the mouth of all his holy prophets since the world began.
22 For Moses truly said unto the fathers, A prophet shall the Lord your God raise up unto you of your brethren, like unto me; him shall ye hear in all things whatsoever he shall say unto you.
23 And it shall come to pass, [that] every soul, which will not hear that prophet, shall be destroyed from among the people.
24 Yea, and all the prophets from Samuel and those that follow after, as many as have spoken, have likewise foretold of these days.
God's church will have prophets:
1 Cor 12:27-28
27 Now ye are the body of Christ, and members in particular.
28 And God hath set some in the church, first apostles, secondarily prophets, thirdly teachers, after that miracles, then gifts of healings, helps, governments, diversities of tongues.
The church of God is built upon the foundation of Apostles and Prophets:
Eph 2:20
20 And are built upon the foundation of the apostles and prophets, Jesus Christ himself being the chief corner [stone];
There were prophets in the church after Christ's death:
Eph 3:5
5 Which in other ages was not made known unto the sons of men, as it is now revealed unto his holy apostles and prophets by the Spirit;