Number of inital labelled samples for ancestry PCA

Hi, I am a bit confused about the number of samples used for the initial generation of the ancestry PCA. In the google spreadsheet from Genetic Ancestry | gnomAD browser, 3457 samples across 1kGP and HGDP under PCA reference individuals. Is my understanding correct, that all the 807,162 gnomAD v4 samples were assigned an ancestry group based on these 3457 samples and 175,043 high quality sites?