The headline sounds like the final end of the experiments but to me it sounds more like a setback, e.g. eventually they hope to get a transgenic blight-resistant tree they can distribute.
It's a setback, but it's a pretty big one, since the whole lineage is now considered nonviable due to OxO replacing another important gene. So you have to go back and implement the gene somewhere else, or do what they talked about here, implement some kind of switch.