From what I read, they are actively working on one, but we shouldn't expect anything to come out until at least 2 months from now. It's annoying yeah, but it's not like they're getting paid to work on it or anything.
In the meantime, you can try to use the wiki pages for translating what you need yourself: for items, there's
this wiki page with the Japanese names listed. Of course there must be some new items in the expansion, but this should take care of most of them.
...and well, yeah, one way or another you do end up missing out on the story and can't play properly. That's why I'm waiting for the translation before buying the expansion, for now I'm just working on puppets I'll import later.