If you mean understanding that the natural laws of the Universe apply equally through out the Universe, then, yes, I agree with the concept. This is easily seen by observation of distant stars and galaxies. They all have distinctive colors, shapes and sizes all according our understanding of the laws of the Universe.
Some may argue about where those laws originated, but I see no reason to dispute those laws as anything but fact. As for rainbows and the Flood, we know many parts of the Bible are either parable or simply the understandings of the Hebrew desert nomads of the time. Just because they didn't completely understand the Universe doesn't prove or disprove the existence of God. Just because the Bible story of Genesis conflicts with the Big Bang Theory and the facts supporting it doesn't prove God didn't create the Universe. It's a matter of perception.
Philosophically, we can ask "If God didn't want us to misunderstand what we should know, why isn't the Bible simply written in the Heavens or on the Moon?" Does anyone who believes in God doubt God has the power to do this? Therefore, from a faith POV, it only makes sense that God chose this method for a particular reason....such as why we don't do our kid's homework for them.
That said, I have no doubt rainbows existed prior to the Flood. Bible scholars date the Flood occurring around 2300 BCE. Moses was born 900 years later in 1400 BCE. That's a lot of story telling around the campfires before Moses was able to write the first five books of the Bible. Anyone who has played the game of "Gossip" knows stories change with the retelling. It's human.