If they can live in such harsh environments the surface world could be a bonanza for them and a disaster for us.
Just the bacteria on the drill casings will be freed to the surface by the billions and we're unlikely to have any resistance to these new critters. Where's my tin foil hat dammit!
“If they can live in such harsh environments the surface world could be a bonanza for them and a disaster for us. “
Actually no. They have adapted to this extreme harsh environment and that is where they thrive. Take them out of that environment and they die as the new environment is harsh to them. A perfect example is the Thermopylae bacteria that live in the boiling springs in Yellowstone park. Take that bacteria out of the springs and it dies.
Actually we have been exposed to these bacteria over the eons. When great meteors hit the earth ejecta from the impact scattered material from deep within the earth over the surface. Do not worry about the bugs deep in the earth.
Click the below link to see the effects of a large meteor impacting the earth.
https://www.livescience.com/56914-dino-killing-asteroid-punched-through-earths-crust.html