If the replacement parts do not meet OEM specifications, a warranty claim "may" be voided. But to deny a warranty claim, the problem would have to be related to the use of the non-OEM spec part, not just some other unrelated part on the vehicle. If you install a non-OEM spec suspension, and you engine starts burning motor oil, then they cannot deny a warranty claim for your installation of the after-market suspension parts.
But if you lowered the car, put on oversize
rims, and put on other non-OEM suspension parts that were not the same as OEM specs, and you had a suspension problem, don't expect them to honor the manufacturer's warranty for the suspension.
If the parts installed are obviously not to OEM specs, and are related to the warranty claim, the proof is on the customer that the after-market parts did not cause the warranty problem, not on Hyundai.