I’m not such a Biblical literalist that I believe there was never a rainbow in the sky until God put one up there after the flood, but still...that the rainbow is used to celebrate debauchery...it’s disturbing.
AFAICR, the rainbow God swore by was the first rainbow of the oath not to flood the world a second time rather than the first rainbow ever, and subsequent rainbows in the sky are declared a reminder of that oath. We can make rainbows with prism lenses, shower heads and garden hose nozzles too, never mind diamonds producing rainbow colors via refraction, and it is likely that such rainbows existed prior to God’s oath in this context too.
There is a rainbow around God’s throne too, and that preceded material creation. The left knows what symbols to steal and to attack, although ultimately to their own undoing.