i'm curious as to what makes YUKI a "former member"? correct me if i'm wrong, but to my knowledge he was active as a support musician (both in recordings and in lives) until abc paused activities due to yasu's health condition. thank you in advance! :)

Acid Black cherry did not pause because of Yasu's cervical spondylopathy. This was misunderstood and mistranslated.
His hiatus is due his damage to his vocal cords, which got more damaged because of singing and headbanging. Yasu was known of having various of serious vocal problems.

Hi could you please provide the source where your information comes from? The official announcement says it is due to his cervical spondylopathy...

The message Yasu wrote himself. He was talking about his "Neck", but everyone who follows him watched the offshots, read interviews etc, know Yasu had lots of trouble with his vocal cords.

If it was just "cervical spondylopathy", we would have seen him back already.

Also the official message says:

yasuの長年の活動から生じた頚椎の損傷、それに起因する身体各所への痛みなど、複合的な症状の併発により、すべての公演を中止させていただくこととなりました。

Due to a cervical spine injury resulting from yasu's activities over the years and the resulting pain in various parts of the body, as well as a combination of other symptoms, we have decided to cancel all performances.

"combination of other symptoms".

However Yasu never mentioned "cervical spondylopathy" himself in the message. But his original writing has been deleted.

This is was the translation of Jin Sono
https://jrockrevolution.com/acid-black-cherry-yasus-letter-08-2017/

However I talked about this with JDA/ABC and some interviews lyric translator kikuko_kamimura.
And she also said: Search "kikuko kamimura" to "JROCKNROLL" on twitter and you find it.

So
"Acid Black Cherry pauses activity due to vocalist yasu's health problems"

is correct.

focusing on the "and other symptoms" instead of the very specific and first condition listed makes this border on a conspiracy theory in my opinion