No, but I did have reason to read up on it.
Yes, there are some promising early results. But WHO rejected the initial toxicology tests because they did not conform to international standards (what I meant by not safe - I perhaps should have written that safety isn't yet established to accepted standards, though that work is being re-done).
Reversals have been demonstrated but not in big enough populations to show it will definitely happen. They test on male volunteers whose wives/partners have undergone tubal ligation, so they are looking at whether a sperm sample looks normal on examination, not on whether pregnancy actually occurs.
Some of the descriptions of time to contraceptive effectiveness are a little odd (I read one claiming immediate, which seems to negate the role of the ampulla), and dose required for effectiveness is also still being refined, as is duration of effect.
But as hormonal methods have proved unsuitable in practice, methods which disrupt sperm transit or viability must be the way ahead. There is still some way to go on establishing if this method will indeed live up to early promise, but with Indian backing (for there is a clear interest in advancing contraceptive technology that country, plus the required scientific competence to do so) and some US interest, it's one to watch. It's certainly not being overlooked.
My guess is that the toxicological issues will be resolved, and I hope reversibility will be properly established. Then it will be down to establishing safe use protocols - like vasectomy, there will be a risk of medical error (doing one tube twice, leaving the other clear) so post-procedure semen analysis would be prudent. Plus more work into duration of effectiveness.