GN didn't say the 150V wiring was at fault. You and several other sites have misunderstood that whole thing. They pointed out that the wire ratings were different to indicate that clearly different parts were used on the two cable adapters (theirs and Igor's). The wire voltage rating has nothing to do with this. They were looking for adapters that were made with the 150V because they were trying to find the ones made like Igor's so they could investigate the solder-area on that differently-made adapter, not the wiring itself.
Also, there aren't different crimps in this style of connector for 150V or 300V (responding to twospoons comment). There are a few different types, and qualities of crimp connections though, between single split and dual split. No idea why. The contacts are all pretty cheaply made for these and being smaller than the old connectors, these are more susceptible to tolerance issues. We may just be seeing the higher fall-out rate of the smaller cheap sockets and connector tolerances. We had burnt cables before, but now we're putting more current on fewer, smaller contacts and the tolerances will matter. That's probably why most cards are fine, but some fall out.