Board Thread:Questions and Answers/@comment-25086462-20160820070717/@comment-26830922-20180126023154

In the more recently released novel "Can't Fear Your Own World" a few more details are revealed:

-Yushiro, Grimmjow, Hallibel, and Nel are alive. The latter three returned to Hueco Mundo where the drove off any remaining Quincy forces after Yhwach's defeat.

-Mashiro is still revealed to be doing well and it is also revealed that the girl named "Kuna" from the Twelfth Division is her younger sister.

-Shino and Ikkaku are indeed blood-related, but it is not known exactly how. Apparently, both their parents died when they were young and they were both shuffled around by their various relatives growing up. So, they are either siblings or cousins. Even though it is unknown which, Shino refers to Ikkaku as her big brother, while he off-handedly states she is either his sister or cousin (apparently not caring which).