From the courts' point of view, I don't see why that would be considered relevant. Assuming the phone was seized properly with a search warrant, there is no legitimate expectation of the secrecy of its contents, no matter how encrypted or secured, all of that data can be legitimately used as evidence and for general investigation purposes.
There is some precedent where courts have used the safe analogy; disclosing the passcodes might be considered analogous to disclosing a safe combination, and forcing that disclosure may violate anti-self-incrimination provisions (such as 5th amendment in USA); however, there's no contest that if the officials are able get access to the safe (or, equivalently, the phone) without that information, they are allowed to do so, and the methods used for breaching the safe aren't really relevant, just as the specific methods for breaching the phone. The evidence would be admissible no matter what method was used so refusing to disclose the specific methods for drilling the safe (or breaching the phone security) would not invalidate the evidence. If the defence would demand that the specific method of breaching that safe must be publicized, any judge would throw that demand out as irrelevant to the case.
The only thing that would matter is that the defence might contest whether the data that the prosecution claims to have been extracted from the phone was really on that phone. But the standard measures for convincing the judge and jury of that - mainly, careful documentation of provenance of any data and careful custody of physical items - generally don't require exposing the details of the specific method. And if the specific data isn't used as evidence but just as information to find some people or physical evidence, then there can be no contest at all if there was a valid warrant for searching the contents of that phone.
The defence has no legal grounds whatsoever to demand that such techniques should be disclosed to the public. They might have legal grounds to require that the techniques used should be vetted, but this can (and is) easily done in a closed manner by having court-appointed experts doing the vetting and testifying "yep, we verified the tool and methodology used and the results match what was on the device" while being prohibited to disclose any commercial secrets about the techniques used.
There is some precedent where courts have used the safe analogy; disclosing the passcodes might be considered analogous to disclosing a safe combination, and forcing that disclosure may violate anti-self-incrimination provisions (such as 5th amendment in USA); however, there's no contest that if the officials are able get access to the safe (or, equivalently, the phone) without that information, they are allowed to do so, and the methods used for breaching the safe aren't really relevant, just as the specific methods for breaching the phone. The evidence would be admissible no matter what method was used so refusing to disclose the specific methods for drilling the safe (or breaching the phone security) would not invalidate the evidence. If the defence would demand that the specific method of breaching that safe must be publicized, any judge would throw that demand out as irrelevant to the case.
The only thing that would matter is that the defence might contest whether the data that the prosecution claims to have been extracted from the phone was really on that phone. But the standard measures for convincing the judge and jury of that - mainly, careful documentation of provenance of any data and careful custody of physical items - generally don't require exposing the details of the specific method. And if the specific data isn't used as evidence but just as information to find some people or physical evidence, then there can be no contest at all if there was a valid warrant for searching the contents of that phone.
The defence has no legal grounds whatsoever to demand that such techniques should be disclosed to the public. They might have legal grounds to require that the techniques used should be vetted, but this can (and is) easily done in a closed manner by having court-appointed experts doing the vetting and testifying "yep, we verified the tool and methodology used and the results match what was on the device" while being prohibited to disclose any commercial secrets about the techniques used.