No I don’t think selling in the US first and having foreign pubs translate the finished us edition is a rule b/c there are books that sold foreign first or were cancelled in US but still sold foreign rights. Aimee Agresti is an example. Gilded Wings #3 was probably cancelled in US (in never published but pub & author have never stated this) but it was published in Germany, so I know the book is done. I think it can be done with an agency & foreign agent team.
it depends on where the author is based and where their main agent is based (since foreign agents largely get the book through their domestic agent connections), i think, but to defend my statement my agent told me that (long story short, i’ve had tons of foreign interest in my books but i couldn’t sell foreign rights before domestic rights since foreign publishers don’t edit but merely translate). so i suppose there could be exceptions (there always are to any rule!) but i don’t think they’re common for mainstream fiction like sj/m. plus, if a book is canceled in the US it’s possible it already went through edits before it sold foreign rights, which would thus make it possible to publish a foreign edition.