The in-kind rule is not going to apply to any kind of crypto. TFA states it's now formally restricted to domestic real-estate.
You could always play with fire and try this for your 2016 and 2017 transactions, but if you get audited, expect penalties.
> Investors in bitcoin and other virtual currencies would lose a lucrative tax break…"
It also reports, without caveats (or attribution to "some say") that the characterization has been used successfully, so far, in the absence of an explicit prohibition:
> Under current law, such trades have been protected under a provision that allows investors to defer capital gains taxes on so-called “like-kind exchanges”
Several of the tax attorneys quoted advance the interpretation that this treatment will only stop on January 1, 2018 under the new bill.
Of course, there's a risk given the ambiguities also mentioned in the article. But the fact that it required legislation, with a future-effective-date, to clarify may give more cover to those using the treatment before that date – and focus discretionary enforcement on clearer cases in 2018.