Installing Linux on a MacBook Pro and waranty
Installing Linux or any other OS on your Mac does not void your warranty as provided here:

https://www.apple.com/legal/warranty/products/embedded-mac-warranty-row.html

The only thing you should be concerned about if anything is the fact that Apple will not provide support for Linux if you choose to install it on your Mac.

If you were to experience issues with Linux on your Mac that you suspected were hardware related, Apple can run a hardware diagnostic on the Mac even if OS X is uninstalled from it. So if you ever ran into an issue where your Mac wouldn't start up as you described in your question, Apple should be able to diagnose the issue and get you a repair provided your Mac is still covered under AppleCare.