This study created memories by non-traumatic means. I believe there is evidence that memories created during, and suppressed due to, trauma are formed and/or stored differently than other memories. Trauma memories are often not fully processed. For non-traumatic memories, or memories that have been processed, it seems reasonable that such memories can be de-prioritized over time. Memories caused by trauma don't seem to fit that pattern.
Another issue in the study is that they used an artificial means of mimicking memory suppression by distorting the visual display of the objects. I'm curious at how they arrived at the conclusion that visually obscuring an object is the same as suppressing a memory, other than the very abstract relationship the two concepts have.
IMHO (or, perhaps, not so humble ;) ), I think these researchers need to spend a little more time and care on how they craft their studies, in order to produce credible and reproducible results, instead of claiming that an experiment done without anyone having memories created by trauma should be used to judge those who have memories created by trauma. This is bad science.