No remains will ever be found. The only thing they'll find are anomalies seen in ground penetrating radar surveys. Those are remains though. Trust and believe. Kill yourself in shame, if you must.

They'll also find graveyards that were already known about, which by definition will have remains in them. As do all graveyards.

This graveyard had wooden grave markers that fell down or rotted over time!? That must mean genocide! Get the anti-Christian pitchforks out boys!

This church served a native community? Doesn't matter! Burn it down anyway.