This discussion is as old as time, or at least 45 years old. The Magnuson-Moss Warranty Act (1975) establishes that a warranty claim can only be denied if causation is established. That bar is set for the party honoring the warranty to clear, not the claimant.I'd still be careful. Someone posted up a bulletin from SOA to their dealers warning them about installing lift kits and that any problems it caused would not be warrantied. The dealers that sell the cars with the lift kits installed, or are willing to install the lift kits, are basically warranting the kits themselves. They charge a hefty premium to do the install so you're basically paying for an insurance policy through them. But dealers being what they are, I'm not sure I'd trust them to actually follow through if push comes to shove.
There is certainly nuance as one has interactions from dealer to dealer, brand to brand, and this is a YMMV moment.
Anecdotally, the experience that I've had has been very positive. I had melted a piston in a tuned turbo motor many years ago (93 Octane tune w/ 91 Octane pump gas will do that). Being very nice to my service advisor and the dealer staff along with a handle of Johnny Walker Red may have helped the repair fall under a warranty claim vs. out of pocket. I can't be sure.