I barely think this will happen in the future!
A bitcoin is always going to have more trust as compared to other coins and ETH especially. This trust will always keep building more and more investors and crypto enthusiast in the favor of bitcoin leading to ultimate investment into bitcoin. So you see here, the weightage for the bitcoin will be always higher as compared to the ETH. I'm completely in favor with the ETH as good investment but it always comes after the BTC. Its perfect currency for long term investment but I don't think that anyone will ever put it in the first rank and that too after having blessed with BTC in the crypto world.