Earlier quoted context omitted.
The good news is that this will mostly affect English, but most other languages are likely to keep being mostly generated by humans. This could even encourage people to use their own language more on the internet, which I think is a win for human cultural diversity. I don't know if there is any escape from this for native English speakers, though.
How so? LLMs like GPT4 have no issue generating text in Spanish, for example.
Probably the larger languages will be affected somewhat as well (I can't test Spanish but I've used GPT3.5 in French without issues) but not as much I think, such automated attacks seem to most often be targeted at English (I suppose if you're doing something like that, it's both easier to use English and also gives better returns (whatever they are) since there are much more English readers on the Internet).
On smaller languages though, GPT is often not good enough to use without a lot of supervision. Like it can give a good impression of West-Flemish, but can't simulate an actual conversation on an actual topic. Even just Dutch is kind of hit-and-miss.