A JV (joint venture) has nothing to do with listing your product.

Even recruiting affiliates (which is the common use of "JV" in the IM world, I'm not sure why) still has no ties to when you get a product listed.

However, if you're looking to setup a launch promotion, your product should certainly be new. It doesn't have to be day 1 (in fact, ideally, it shouldn't as you want to test conversions, confirm your sales process and build testimonials etc) ... but it should be new.