I'm familiar with this particular attack, as it was discussed here previously. It's a worthwhile attempt but the identification as star names, if real, hasn't been confirmed. But your reservations are justified.
More generally, has any attempt been made to identify the meanings of words in any sufficiently large corpus of text in a known foreign language (for example, Finnish), without being provided with a translation into English, and then compare the identified meanings to the actual meanings, as a first step towards translation?
There was a paper where they trained word vectors for English and Chinese at the same time. But they forced a few Chinese words to have the same vectors as their translated English words. This gave accurate translations for many Chinese words that didn't have translations.
Doing this without any translated words at all, would be more difficult. But I believe possible. It's actually a project I want to try in the near future.
More generally, has any attempt been made to identify the meanings of words in any sufficiently large corpus of text in a known foreign language (for example, Finnish), without being provided with a translation into English, and then compare the identified meanings to the actual meanings, as a first step towards translation?