I linked it in another comment, but it depends on how pedantic you are. This video does agree the battle flag had growing popularity, but it isn’t technically the same as the currently used Confederate flag (nor was the Navy Jack). The battle flag was more square and not as wide, the Navy Jack had a different blue.

Though if you say “close enough” I wouldn’t fight it.

Edit on second read through, your statement was only on the battle flags popularity affecting the fi al design, which does make your statement correct.