So you rule out the discovery of extant life (such as at the bottom of the ocean) with a different origin?
No that isn't impossible.
I said that above....
No it's not out the question. It would be a fascinating discovery. It doesn't change the simple fact that every living thing ever discovered from humans to bacteria to blades of grass all evolved from a common ancestor over millions of years. Not one single species or anatomical feature or biochemical pathway requires an intelligent design explanation
So to summarise. The deepest roots of the tree of life might lead to multiple origins. If that is true then every species now known still descended from a common ancestor. If there is some undiscovered prokaryotic species that has remained aloof all these millennia that would be amazing but it would not change the simple fact of evolution any more than the discovery of life on another planet would do so. We would then have more than one parallel story of evolution to tell. That would be very cool.