Without knowing the specifics, it's difficult to comment upon what countries would not agree and the reasons they might not agree, but that would need to be carefully assessed against the requirements of accountability. So it is certainly something that would be of interest if there are any large numbers of democratic countries that would be refusing to enter into such an agreement.
On the other hand, would it equally be of interest if this were simply one or two isolated incidents? More information is needed. And on the issue of timeliness, again, what the law attempts to achieve is a framework of general guidance. Will it cover each and every situation? Perhaps not, but the law attempts to achieve the best balance it can using the words that are available to us to create this general framework.