I am tempted to think that astronomy mattered to the main story thread in both the translations and the originals even if vocabulary changed, but this is just a hunch and I defer to those who have looked at the texts.
There is a difference between the use of star patterns as an aid in relating a narrative and the technical aspects of astronomy.
The former is an adjunct to a language which may have no written form and the stars (and other heavenly bodies) provide a universal, worldwide, timeless canvas upon which to tell the story.
The latter is a timekeeping mechanism for specific purposes.
The Epic may have been explained by some through a relationship with cosmic entities but conflating that with genuine astronomy would be unlikely to yield any meaningful results in regards to geographical location.
However, there may be a connection between the original mystical practices at the Temple of Baal with the later Roman reconstruction and the renaming to Heliopolis.
When the gods created Gilgamesh they gave him a perfect body. Shamash the glorious sun endowed him with beauty, Adad the god of the storm endowed him with courage, the great gods made his beauty perfect, surpassing all others, terrifying like a great wild bull. Two thirds they made him god and one third man.