Apple release a memo to all their employee saying Apple products with a third party display component but having a function issue unrelated to the screen will still be covered under the warranty package.
It means you can get a third party replacement screen without voiding the standard warranty. But if they found the issue is related to the new screen, you will have to pay an out-of-warranty price to fix it. The changes apply to the United States, Canada and some other countries around the world.
But Apple employees will inspect the device for the red flags. The red flag is an indication to detect fraud or tampering. Apple has at least two patents to detect any action tampering the device and detect any exposure to any form of liquid with Liquid Submersion Indicators (LSIs) which located at a specific section of the device.