Don’t disagree with that, especially after Froome himself had said the details would be released...but not sure who to blame here; UCI/WADA or Froome/Sky. Or both?
Some of both, I'd say. WADA did not want the details released (see below), but I don't think they could have stopped Froome from releasing them, or if they could, he should have pointed that out as a reason for not doing so.
Not sure of the reasons to withhold either..could the details be seen as a blueprint for future doping, or were they (UCI/Wada) concerned about possible action from those unfairly sanctioned in the past?
Mostly the former, I'm pretty sure. WADA mentioned this at the time. One problem with this is that athletes who are really taking salbutamol for a genuine need, and not to dope, would benefit from these details. They have a right to know what kind of risk they might have, what exactly the relationship is between the doses they're taking and the likelihood of triggering an AAF.
Froome's case actually makes this worse. His salbutamol levels might have been judged possible just from inhaling at the allowed dose, but at the very least we can say that most of the time that level would be indicative of going well beyond the allowed dose. How are you going to change the rules so that another Froome case would get off? You would either have to raise the maximum allowed urinary level, in which case far more abusers would slip through, or require athletes to show how much they inhaled and when (as Froome allegedly did). The latter is cumbersome--you're asking a lot of athletes to keep detailed records of their use--and athletes at the least would have to know a lot more about salbutamol than has been published to understand the situation.
Another point is that these details will come out eventually, anyway. There's talk about changing the salbutamol maximum dose allowed, or the dose per time, whatever. To do this, there has to be data showing that a new maximum is fairer, and will result in fewer false positives, while still catching abusers. But that data will have to get published. All the salbutamol studies by anti-doping researchers in the past have been published, and I don't see how that would change. I don't think WADA could announce a new maximum without any public data to back it up.
in fact, being secretive could increase the risk they're trying to avoid. An athlete who wants to take salbutamol for PE could challenge even the new rules, whatever they are, arguing that without public data to back it up, it could be unfair to genuine asthmatics. When you're dealing with a drug that can be taken under reasonable circumstances, for a medical need, but also as PE, you have to be transparent about where and how you draw the line.
Edit: I started out intending to write a brief answer, but the more I think about this, the more I realize how changing the salbutamol standards is going to be very difficult. I don't remember if it was you or someone else who said upthread that the outcome might just be there won't be any prosecution of salbutamol cases for a while, but I tend to agree. Even without knowing all the details of Froome's case, athletes do now have a basis on which to challenge any levels over the maximum.