I'm not really buying this, that there is going to be a S1Hii (or a S0). Of course I could be wrong, but Panasonic has invested so much in the S1R II to be their Flagship camera, it doesn't make sense to me they would immediately invest even more to introduce a new and improved Flagship camera. This would undermine their investment in the S1R II, plus the price would be quite a bit higher so it would sell to a smaller crowd with diminished return on investment. The S1R II is close to a perfect photo camera and close to a perfect video camera. And at a super competitive price. The video guys are going to love the S1R II, Gerald Undone be dammed, and it will sell well.
Remember I'm coming from an A1. Why would Lumix go to a stacked sensor and suffer reduced dynamic range and maybe lower image quality? The current sensor is optimum for most situations. And I operated with the S1H for quite some time, and I only used synced timecode a couple of times - and that was just to show it could be done. My S1H suffered moiré now and then, maybe not as much a camera without a low pass filter, but to me the best control is for the operator to change shooting angle or range to control moiré. Also, moiré control is different for different situations, and it would be a mistake for Lumix to use the same low pass filter as the S1H. RED video cameras have interchangeable low pass filters - for some future camera Lumix might want to do this.
It seems to me Lumix should work on upgrading the S1R II, do what it can with firmware upgrades, but for hardware upgrades bring them out with model upgrades, the S1R III, the S1R IV, etc. The next model, maybe a couple years out, could have a larger and faster buffer to better handle sports and wildlife, and maybe better battery life. And on and on. That way they have one Flagship camera that keeps getting better and better.