Bhagavad Gita, Chapter 11, Verse 47

The Deity said: Graciously have I shown to you, O Arjuna, this Form supreme, by My own Yoga power, this resplendent, primeval, infinite, universal Form of Mine, which has not been seen before by anyone else.

What Arjun witnessed is named here as genuinely unprecedented, not shared with anyone who came before him.

Krishna states plainly that this vision was real and rare, made possible through a specific divine power, not something anyone else has ever been granted. That real exclusivity underlines how significant the moment actually was.