In Guardians of the Galaxy vol. 2, Ego refers to himself as a god. In Eternals, they worship Arishem like a god, Ajak says "I respect your grand design Arishem," Sprite asks "Why did Arishem make me this way?" and Ikaris says "I exist for Arishem as do you." In Love & Thunder, two with the other gods. So would Gorr's wish have killed Arishem and the rest of the Celestials?
Thor says, "If he seeks the that means he could wipe us out at once." Altars are for gods. Gorr says "I put my faith in a higher power hoping it would save her, and she died. Now I understand my daughter is the lucky one. She does not have to grow up in a world of suffering and pain run by wicked gods." So when Gorr kneels before the body of Eternity, does Gorr think of Eternity as a "higher power" and a god?
Finally, in the aftermath, Korg's monologue about Jane says There does not seem to be any reason why killing Thor, Zeus and other gods of that level would put the universe at risk of destruction. But killing Arishem and Eternity might. Besides, this wasn't even Gorr's idea -- it was the voice of the Necrosword's idea, so Gorr might not fully realize what would happen.
So ... would Gorr's wish have killed Eternity, Arishem, and the universe?