(I'm not an astrophysicist). They possibly are referring to the initial age of the universe times the speed of light (13.8 billion light-years), as if it was static.
Like you infer, "[...] stuff is everywhere, light goes at c, stars and galaxies move, and the Universe is expanding."
https://www.forbes.com/sites/startswithabang/2018/02/23/if-t...