I wrote that paragraph of the blog post, and I think I didn't phrase it correctly. What I meant to say is that we hacked Jepsen tests to support RethinkDB, and then ran the tests internally for months. I added that note late last night, definitely could have phrased it better.
We've been working with Kyle on this though, and I think he seemed happy to merge the PR (but he's pretty busy). Hopefully will happen soon, sorry for confusion.
EDIT: here is some context -- https://github.com/rethinkdb/rethinkdb/issues/1493#issuecomm....