That speaks of what will take place after the New Heaven and new earth of the Millennium has finished serving its purpose.
For the Millennium is also called a new heaven and new earth!
No, there is no Millennium after Jesus's returns. The thousand years represents a timeframe that began at Jesus's sacrifice/resurrection and goes until His return at the last day - it is a symbolic number, not a literal number. When the seventh angel sounds all things will be completed; the seventh angel sounds at the last trumpet, after which, there will be time no longer, so there cannot be another literal thousand years after that, only before it. The last day is judgment day - either unto eternal life for the saved or the second death for others.
[Jhn 6:39-40 KJV]
39 And this is the Father's will which hath sent me, that of all which he hath given me I should lose nothing,
but should raise it up again at the last day.
40 And this is the will of him that sent me, that every one which seeth the Son, and believeth on him, may have everlasting life:
and I will raise him up at the last day.
[Jhn 11:24 KJV]
24 Martha saith unto him,
I know that he shall rise again in the resurrection at the last day.
[Jhn 12:48 KJV] 48 He that rejecteth me, and receiveth not my words, hath one that judgeth him: the word that I have spoken,
the same shall judge him in the last day.
[1Co 15:50-55 KJV]
50 Now this I say, brethren, that flesh and blood cannot inherit the kingdom of God; neither doth corruption inherit incorruption.
51 Behold, I shew you a mystery; We shall not all sleep,
but we shall all be changed,
52 In a moment, in the twinkling of an eye,
at the last trump: for the trumpet shall sound, and the dead shall be raised incorruptible, and we shall be changed.
53 For this corruptible must put on incorruption, and this mortal [must] put on immortality.
54 So when this corruptible shall have put on incorruption
, and this mortal shall have put on immortality, then shall be brought to pass the saying that is written, Death is swallowed up in victory.
55 O death, where [is] thy sting? O grave, where [is] thy victory?
[Rev 10:6-7 KJV]
6 And sware by him that liveth for ever and ever, who created heaven, and the things that therein are, and the earth, and the things that therein are, and the sea, and the things which are therein,
that there should be time no longer:
7
But in the days of the voice of the seventh angel, when he shall begin to sound, the mystery of God should be finished, as he hath declared to his servants the prophets.
[Rev 11:15-18 KJV]
15
And the seventh angel sounded; and there were great voices in heaven, saying,
The kingdoms of this world are become [the kingdoms] of our Lord, and of his Christ; and he shall reign for ever and ever.
16 And the four and twenty elders, which sat before God on their seats, fell upon their faces, and worshipped God,
17 Saying, We give thee thanks, O Lord God Almighty, which art, and wast, and art to come; because thou hast taken to thee thy great power, and hast reigned.
18 And the nations were angry,
and thy wrath is come, and the time of the dead, that they should be judged, and that thou shouldest give reward unto thy servants the prophets, and to the saints, and them that fear thy name, small and great; and shouldest destroy them which destroy the earth.
