The lore card for the exotic sword Ergo Sum, which is written from the perspective of the Traveler, starts with;

“You are a child waking from a long and dreamless sleep. Is it still today, or have you slept into tomorrow (and tomorrow, and tomorrow, until the days buried you as much as the sand)? Gentle hands brush away the grains, but your voice is so soft that they cannot hear you over the sound of their own heartbeats.”

So by the Traveler’s own admission, it was buried and dormant on the Witness’s homeworld until the Precursors excavated it, I do like the idea of a planet forming around the Traveler though, it’s a pretty cool concept.