That's true but if a reputable journal publishes this before that verification is in and it ends up being mistaken or even a hoax or fraud then their reputation will be dinged so with the stakes this high given the material and the visibility there is a fair chance that they will indeed wait for independent replication before committing to publishing it. But I don't see it happening during the peer review process itself, it will happen simply because another lab tries the same and gets lucky (or not, in which case the whole thing will blow over).
The journals reputation will be dinged if it comes to light that they have not adequately performed their due diligence. Which, as has been explained above, does not include replication.
If you require replication for publication practically nothing will get published ever. Once published, others will attempt to replicate, and it is the authors' reputation on the line if nobody manages to replicate it following the paper and consulting with the authors.
They are not going to replicate this themselves, obviously. But extraordinary claims etc, and this one is about as extraordinary as they come. Papers that are non-controversial even if they might turn out to be wrong get published all the time. But papers where 95% of the scientists out there are going to be super skeptical will find it much harder to get published. Both the authors and the publishers have a reputation to protect. Keep in mind that the peer-reviewers will have to sign off on the publication as well.
It would be a variation on what's already out there right now. And the whole problem is that the recipe is vague, in other words even if they have a working sample they don't know exactly what goes into making it.
