At risk of stating the blindingly obvious, I will start by saying this steward never existed. He is a character depicted in a parable but who could easily have found many actual counter-parts in real life. The parable used current knowledge of affairs so that the hearers would be helped to grasp the point Jesus was making, which had nothing to do with secular business matters, but with eternal, spiritual truths to do with the kingdom of God. There’s always the danger that we today, in this year of Covid 2021, will think in terms of how things are in our particular society, both secularly and religiously, and so miss spiritual truth.
To deal with the main part of your question and to demonstrate the difficulty, I partially quote from the NIV Study Bible notes on verses 1 to 3 (1987 edition).
“The dishonest manager (v.8) had no scruples against using his
position for his own benefit, even if it meant cheating his master.
Knowing he would lose his job, the manager planned for his future by
discounting the debts owed to his master in order to put the debtors
under obligation to himself. Interpreters disagree [my emphasis] as to
whether his procedure of discounting was in itself dishonest. Was he
giving away what really belonged to his master, or was he forgoing
interest payments his master did not have a right to charge?
Originally the manager may have overcharged the debtors, a common way
of circumventing the Mosaic law that prohibited taking interest from
fellow Jews (Dt 23:19). So, to reduce the debts, he may have returned
the figures to their initial amounts, which would both satisfy his
master and gain the good favour of the debtors. In any event, the
point remains the same: he was shrewd enough to use the means at his
disposal to plan for his future well-being.”
A differing interpretation is found in a commentary 300 years old, that of Matthew Henry. He takes the view that the steward embezzled his master’s goods, then was too slothful and proud to work honestly after a disgraced discharge, using cunning (shrewdness) to keep himself in the manner to which he had become accustomed. But Henry stresses the spiritual points and application:
“This our Saviour is here pressing to us, by reminding us that we are
but stewards of the manifold grace of God, and since we have in divers
instances been unfaithful, and have forfeited the favour of our Lord,
it is our wisdom to think how we may, some other way, make what we
have in the world turn to a good account… We are liable to the same
charge [as that made against the steward]… Our discharge from our
stewardship at death is just… that when our stewardship is taken from
us we must give an account of it to our Lord: After death the
judgment.” (p1500)
Now, this is where your main question requires comment, for the shrewdness of the steward was not commended either due to his provision for his future, or any change of heart. Both were utterly selfish things on his part and the Lord would not commend him for either. Note, it was the steward’s master who expressed comparative approval of his cunning steward, albeit his actions were totally selfish. There was no change of heart on the part of the steward. He simply carried out a damage limitation strategy to save his own skin.
And this is where Jesus’ spiritual application is vital to grasp, requiring us to read through to the end of chapter 16, no less. Why? Because during this public discourse, the Pharisees were present, as you point out in your comments, hearing Jesus’ warnings about covetousness in unrighteous wealth indicating unfaithfulness with spiritual wealth. They knew the point Jesus was making, for they loved money. That galled them, so they ridiculed Jesus, as Henry points out:
“As their sin, and the fruit of their covetousness, which was their
reigning sin, their own iniquity. Note, many that make a great
profession of religion, have much knowledge, and abound in the
exercise of devotion, are yet ruined by the love of the world; nor
does any thing harden the heart more against the word of Christ. These
covetous Pharisees could not bear to have that touched, which was
their Delilah, their darling lust; for this they derided him,
exemykteri-zon auton – they snuffed up their noses at him, or blew
their noses on him.” (page 1501)
Therefore, we must take note that Jesus went on to ‘draw the curtain’ to show that other realm where different states obtain for those who either have the Lord’s favour, or who forfeit it by their love of mammon – the downfall of the rich man in the last part of Luke chapter 16.
Summary:
The first part shows no providential care for any but the bad steward – even when found out, he only appeared to benefit others for his own good, not theirs. Nor did he have a change of heart because all that he did was just as selfish and self-centred as before he was caught out.
The second part shows Jesus exposing the love of money, but he did not commend the selfish steward. The steward’s equally money-loving master displayed the truth, “It takes one to know one”. He gave a back-handed compliment but Jesus went on to effectively condemn both characters in the parable.
The third part is the one you do not include in your consideration of your question, but which is the most important part – the rich man and poor Lazarus dying and finding themselves in different ‘parts’ of the spirit realm (prior to the day of resurrection and judgment). This was squarely aimed at the money-loving Pharisees (and to all who are lured astray by material wealth), sons of this world. But sons of light must be far more judicious in their use of God’s grace and all that is entrusted to them, than worldly people are with mere material things. Wealth is never righteous, hence it is called “unrighteous wealth” and it will utterly fail. What then for professed believers in Christ who frittered their time and material goods in daily living without caring far more for growing in spiritual grace and being charitable and gracious, out of a sincere heart, to others?