Well there is a probability for that to happen but i don't think that it will happen right away. You see bitcoin took a lot of years to be in where it is right now. So i think ethereum will take about a couple of year to take over bitcoin.
But bitcoin is not going to remain static either, in this year many people were predicting that ETH was going to surpass bitcoin in market cap and suddenly out of nowhere bitcoin grew a lot and now there is a huge difference between BTC and ETH and the same may happen again if ETH gets close to bitcoin once again.
ETH will not completely surpass the Bitcoin because ETH is just close to bitcoin but it is not enough to replace the bitcoin because it has vulnerability that can be the reason for the people to not transfer to ETH because back in the past few weeks, it has been hacked and a lot of money is stuck so that is maybe a huge issue for the people to fully trust ETH.