Definitely was. Yhwach is verbatim stated to be a coward. He lacked the courage to stand up and face death like a man, unlike Ichigo. Him acting like a coward in his final moments fits the overall narrative Kubo wants to portray.
That’s the whole point of the almighty. Along with its biblical symbolism, it’s a pretty good representation of the character. The almighty allowed him to never face death. It’s powernull is symbolic of “no weapon shal prosper against Christ.” It’s fate manipulation is symbolic of Christian fatalism, and omniscience, whilst also showing how Yhwach feared death so much, his ability allowed him to flawlessly avoid it. His resurrection is symbolic of Christs resurrection and his own fear of death, he could never truly face it. Without his Almighty (due to still silver), he was without his shield from death, he was forced to face death, and his fear overcame him.
Hell, he is even symbolic of heaven. Why do people desire heaven? Well, at least one of the motives is the immortality and eternal pleasure of heaven. Humans naturally view death with fear. We fear death and wish for true immortality, which Christ and heaven gives us. Maybe, we fear the unknown of death and use heaven as a coping method. This symbolism is beautifully represented in bleach.
Yhwach is symbolic of Jesus. Jesus is a leader of humanity who will guide us into heaven. Yhwach is the same. Yhwach wishes to lead all beings in bleach into his new world without life and death, clearly symbolic of heaven. He also represents the reason we desire Christian heaven, that being fear of the unknown (death). Ichigo provides opposition to this well. His first poem is “We fear the unknown.” Despite this fear Ichigo is able to muster the courage to face certain doom (the overbearing power of Yhwach) with a brave face, perfectly opposing Yhwachs fear. Yhwach is the fear and despair to Ichigos courage and hope.
Yhwach and his downfall is supposed to be a critique on a fear of death and a criticism on god. Hell, even Aizen and Yhwachs dynamic pushes this. Yhwach is a critique on the fear of death, heaven, and the idea of letting go (Yhwachs goal can also be interpreted as Buddhist nirvana/liberation, Kubo likes using Buddhist references in Bleach. Nirvana is the idea of letting go from the world to reach paradise, which fits Yhwach). Yhwach being scared in the way you described is not only pushed this theme, it just works for the character.
Sorry for the tangent