Besides, the opening crawl says “first major victory”. I didn’t expect the Rebel alliance to have had absolutely no success against the Empire before that, I just expected it to be smaller victories, which is what we see in Rebels.
What?
It is a period of civil war.
Rebel spaceships, striking
from a hidden base, have won
their first victory against
the evil Galactic Empire.
And yes, you could lawyer your way out of the victory on Lothal, but that’s weasel words.
The point is that I can’t imagine they will hold to a single brief line from a less-than-popular movie if it means keeping the main character out of the show.