These passages aren't in the future tense. If the current earth and heavens is destroyed then God's promises in these passage have failed.
The 2nd Temple had a sea. Gentiles are typified as the sea. So?
Talk about stretching!!! No, His promise that the earth remains will never fail---He does have the power and the promise He has made to change them --- to remake them. You don't tell the potter what He can or can't do with His own clay! There is nothing about the sea in the passage to mean anything other than --the sea!! It is talking about the earth and the heavens, not about a temple----that's later, and the word temple is used, not sea.
This certainly has not happened either. All are alive and well.
Rev 21:4 And God shall wipe away all tears from their eyes; and there shall be no more death, neither sorrow, nor crying, neither shall there be any more pain: for the former things are passed away.
And neither is this anywhere on this earth:
Rev 21:10 And he carried me away in the spirit to a great and high mountain, and shewed me that great city, the holy Jerusalem, descending out of heaven from God,
Rev 21:11 Having the glory of God: and her light was like unto a stone most precious, even like a jasper stone, clear as crystal;
Rev 21:12 And had a wall great and high, and had twelve gates, and at the gates twelve angels, and names written thereon, which are the names of the twelve tribes of the children of Israel:
Rev 21:13 On the east three gates; on the north three gates; on the south three gates; and on the west three gates.
Rev 21:14 And the wall of the city had twelve foundations, and in them the names of the twelve apostles of the Lamb.
Rev 21:15 And he that talked with me had a golden reed to measure the city, and the gates thereof, and the wall thereof.
Rev 21:16 And the city lieth foursquare, and the length is as large as the breadth: and he measured the city with the reed, twelve thousand furlongs. The length and the breadth and the height of it are equal.
Rev 21:17 And he measured the wall thereof, an hundred and forty and four cubits, according to the measure of a man, that is, of the angel.
Rev 21:18 And the building of the wall of it was of jasper: and the city was pure gold, like unto clear glass.
Rev 21:19 And the foundations of the wall of the city were garnished with all manner of precious stones. The first foundation was jasper; the second, sapphire; the third, a chalcedony; the fourth, an emerald;
Rev 21:20 The fifth, sardonyx; the sixth, sardius; the seventh, chrysolite; the eighth, beryl; the ninth, a topaz; the tenth, a chrysoprasus; the eleventh, a jacinth; the twelfth, an amethyst.
Rev 21:21 And the twelve gates were twelve pearls; every several gate was of one pearl: and the street of the city was pure gold, as it were transparent glass.
Rev 21:22
And I saw no temple therein: for the Lord God Almighty and the Lamb are the temple of it.
Rev 21:23
And the city had no need of the sun, neither of the moon, to shine in it: for the glory of God did lighten it, and the Lamb is the light thereof.
Rev 21:24 And the nations of them which are saved shall walk in the light of it: and the kings of the earth do bring their glory and honour into it.