Sometimes you will here phrases like, “He’s a changed man” or “He’s not the person he used to be.” These phrases have real content and meaning, but it is clear that they don’t mean a previous person has gone missing and has been replaced with a new fraudulent person.
In this sense we can say everyone who is in heaven is a different person than when they lived on earth.
Now regarding morality - that is, behaviors - this is an important point. Everything that we do now that is immoral (to use your examples, gossip, pride, workaholic, lazy, prone to gambling) - these are not things that define us. They are disordered behaviors resulting from our fallen condition. If we define ourselves by these disordered behaviors, then we are missing what is truly important. In all truth, when these disordered behaviors are stripped away, then we see more and more clearly what we really are, what our true personality is, what our true purpose and meaning is.
For example: if one gossips, then the removal of the habit of gossip may reveal that this person has a special capacity for conversing meaningfully with others. If one is prideful, the removal of pride may reveal a specially magnanimous person or someone who is meant for leadership or great works.
If we define ourselves by our true nature - that we are human beings made in the image of God - and make this the standard for the way we live our lives, we will find that the difference between who we are here on earth and who we are afterwards in heaven is not so drastically different.