I just skimmed over the page but the "4K Project" only appears to be a 28-minute special consisting of scenes from each movie, the individual airings of the movies themselves don't appear to be from 4K masters.

It'd make for a cool comparison, but I don't have cable. My GF does, but there's no way to directly record from the cable box. It would be possible if she was willing to spend an extra 5,000 yen a month to rent a special BD recorder/cable box, but lately she's doesn't even seem to want to pay what she's paying now.

But the bitrates on Japanese cable usually suck, and I'm sure these will be coming to home video eventually. The recent BDs were likely just a cash-in for the new movie, Toho will definitely want to get people to double-dip again.