I'm aware that the folks at Bletchly park were very good at their business of reading German codes, but that doesn't mean the Japanese weren't sending their info to Tokyo and the allies weren't reading those messages.
I don't know the facts in this specific case as I'd not heard of it before but it's quite likely that those messages you refer to were passed direct to the Japanese section at Bletchley Park for deciphering. As I pointed out earlier, this included a large American contingent. I only discovered this during my recent visit as it was never common knowledge. Everything done at Bletchley during WWII was classified as Top Secret & some still is today. Lack of knowledge of what was actually achieved there (like the development of the first electronic computer) has led to many misconceptions since the war. All equipment & documents were destroyed soon after the end of WWII to prevent it falling into the hands of a potential enemy. I don't expect this is unique by any means & there are some things that will never be revealed, at least during my lifetime.