I have been thinking about this for a while and wanted to get some reactions from people who work in SEO or build for ecommerce.
The entire multilingual SEO industry is built around one assumption. Translate your pages, create /fr/ and /de/ URLs, set up hreflang, and you are discoverable in every language. That works for Google because Google ranks pages and crawls URLs.
But AI search engines like ChatGPT, Perplexity and Google SGE don't work that way. They don't rank pages in the traditional sense. They try to answer a specific question about every product they encounter which is: what is this thing, and what is it called in different languages and contexts?
The field that carries that answer in Schema.org is alternateName with language tags. It looks like this: