That... is exactly how a language is expanded, "set phrases" are established and dialects are born.
If Toki Pona was used as an actual language in an everyday setting in a community, it would quickly get set, established terms and phrases for things, and essentially expand the vocabulary.
The Roman Catholic church uses Latin for official definitive documents so they presumably have ways of expressing at least some modern concepts.
"Reginald Foster, a former plumber’s apprentice from Milwaukee who, in four decades as an official Latinist of the Vatican, dreamed in Latin, cursed in Latin, banked in Latin and ultimately tweeted in Latin, died on Friday at a nursing home in Milwaukee. He was LXXXI. "
Or the community would literally just expand the vocabulary directly, unless toki pona has mechanisms to preempt this which doesn’t seem to be the case. Except for the scripts, which both seem to be ideographic, but even then nothing precludes creating new ideographs.
And inevitably at one point something like "hot brown water" will become a single term for coffee. And then it will be contracted into something like "hobrow" because the original term was too long :)
If Toki Pona was used as an actual language in an everyday setting in a community, it would quickly get set, established terms and phrases for things, and essentially expand the vocabulary.