Yes, it was guaranteed to kill him since knowledgable fellow Gold Saints (even ones canonically stronger than him) know so, the fact that Gold Saints can be hurt and killed by way weaker attacks, and the fact that Shaka says to himself he'll die taking them on even before AE was in his equation. It takes AOT ending defender mental gymnastics to think a character would lie talking to himself. Shiryu literally blew away the AE towards the sky and it didn't hit anyone. I can't believe you try to poke plotholes in 8th sense users being able to revive while somehow thinking Gold Cloths can tank AEs, something that would ceate more plotholes with the story than anything I've ever heard regarding the story.
"Exist as a soul" so did he die or not? But yeah, he was a soul in that moment, because he died.
Definitely not the case for the goddess in a regular human body Saori as also evident in the all the reactions from everyone (not just the Saints, the Underworld army's side too), she took her own life to awaken the 8th sense in the first place in the act of mimicking Shaka, and came back to life, something she clearly wasn't capable of prior.
Maybe if Shiryu said it (since he was actually there), but Hyoga at that time wasn't even on the scene for the AEs to exactly know that information. 3 Gold Saints on scene confirming the Virgo Cloth should've been annihilated and not being the least bit surprised when given the impression it was when Shura swung through him>>>.
But let's say even if that were really case (despite the ridiculous scaling inconsistencies it would create to believe that the Virgo Cloth would tank an AE), that still wouldn't prove that by some plot twist all the talk about Shaka dying was a lie, since Gold Saints can die from the force of attacks that don't destroy the Cloth.