What do you understand the reason Genesis 1:16, "he made" being added, not being in that Hebrew text? The stars literally became visible on the fourth day too.
Genesis 1:16
And God made two great lights;
the greater light to rule the day, and the lesser light to rule the night: he made the stars also.
As I read it, it literally says, “God made two great luminaries; the greater to rule the day, the lesser light and the stars to rule the night.”
As far as these are concerned it clearly states that the greater were made on this day. The two of them were great, in comparison to what other bodies of light it is not immediately connected. They are clearly seen to be greater than the stars. A person need only to make comparison for themselves. Without perspective, it is difficult to use words that show comparisons (as the word great).
The word light on day four is different than day one except in verse eighteen where it refers back to the day and night. The usage on day four is that of a body of light and not merely the light.
The greater body rules the day the lesser rules the night. At this point the English uses the colon to show a direct correlation with the previous portion of the sentence. As I understand it, the sun was made to rule the day. The moon was made to rule the night: also the stars. (As in the stars were also made for the night. They do not rule because they were not made to and so are somewhat separated from the two greats.)
From the Hebrew, I lean towards the bodies of light being made on the fourth day.
It was the bodies that were made on day 4. The light was already in existence.
The lack of the statement that the physical stars were made doesn’t mean that they were there or that they were not.
It not having much to do with doctrine, I am content to discuss it without coming to any definite conclusion.