It only means they all stopped existing on earth not having received the promises.
Thank you for granting that the passage does say that Enoch died. Yes, I would agree that it does mean that they no longer existed on the earth, not having received the promises (and I understand that what you mean).
With that agreed upon, may we talk about the next part then? What are the promises? And why would Paul say that they died, not having received the promises, if they had already received the promises at the time he was speaking?
Titus 1:1-2 KJV
(1) Paul, a servant of God, and an apostle of Jesus Christ, according to the faith of God's elect, and the acknowledging of the truth which is after godliness;
(2)
In hope of eternal life, which God, that cannot lie, promised before the world began;
1 John 2:25 KJV
(25)
And this is the promise that he hath promised us, even eternal life.
We can go a bit further here, as Paul continues to tell us that Abel, Enoch, Noah, Abraham, and Sara also... still have not arrived at their heavenly country.
Hebrews 11:16 KJV
(16)
But now they desire a better country, that is, an heavenly: wherefore God is not ashamed to be called their God: for he hath prepared for them a city.
If they already had this better country, they would not be said desire it, as they would have it as a possession. Paul comes back to this theme after some elaboration, and reiterates that they received not the promises, but that we would be perfected together, not apart from each other.
Hebrews 11:39-40 KJV
(39) And these all, having obtained a good report through faith,
received not the promise:
(40) God having provided some better thing for us,
that they without us should not be made perfect.
This agrees with the promise of eternal life, promised before the world began, realized through the resurrection of the dead, at the last day, all together, with the trumpet and the voice of the archangel, yet not before.
Consider the symbolism of the figures we are given and the parables:
1. When the walls of Jericho fell down, it they come down in a trickle, or all at once with the combined trumpet blast?
2. When Jesus returns from the far country, having received the kingdom, does he then bring his reward to his faithful servants, or was he slowly sending lucky lottery winners prizes in advance?
3. When we are told of the marriage of the bride and the Lamb, is this an all-at-once spotless bride and shining groom event, or is this better likened to "living together" for some many years before finally agreeing to "tie the knot?"