It means that the cold shutdown lie is dead. Tepco/Japan just does not want to give up on that dead horse yet. They are claiming sensor failure and that temperature is not the main metric to determine Cold Shutdown Conditions. These Japanese Nuclear engineers are starting to sound like Global Warming proponents. Warmth causes snow - Temperature has nothing to do with Cold Shutdown.
The main problem with the high temperature readings is that it means they have no clue as to what they are doing. But hey, some of us already knew that. We are in uncharted territory. We need to know what is causing the high temperature. It could be heat coming out of the hole where the corium melted reactor mess is digging into. Or it could be heat from some of the remaining as yet unmelted core that still resides in the RPV with a big hole in the bottom of it. And recriticalities have been ongoing. They have measured radioactive iodine around Japan off and on ever since last March. You see, once the core melts, there is no containment and no shutdown. The control rods have also melted.