Crazy assumption. Yes, it’s true for the English speaking world, but it’s much more nuanced outside of it. Here’s a map from Wikipedia:
https://en.m.wikipedia.org/wiki/Long_and_short_scales#/media/File:EScalas_corta_y_larga.svg
Keep in mind that your link to wiktionary only covers languages where it is spelled exactly “milliard”.
Yeah, but only forward in time