Regarding the first post, the mekubal who first mentioned this discussed just the fact of the uniqueness and segula of “9”. In fact, my understanding is that there are people who every year consider the 9th day of Kislev to be an eis ratzon. It does not have to also be the 9th year of yoivel, although that would make it additionally auspicious.
Which brings me to the next issue: If next year is shmitta, how could this year be the 9th year of yoivel? Hmmm. Moreover, the Kupath Ha’ir literature states that Rav Kanievsky supposedly indicated that 5756 was the 40th year of the yoivel and that therefore 5765 was yoivel and thus this year is the 9th year of yoivel. But, if you make the calculation, if 5756 was the 40th year of yoivel, then 5765 would only be the 49th year of yoivel and yoivel would not be until 5766! That means that the 9th year of yoivel isn’t til next year! Hmmm, again.