Though the burden of proof is on the dealer/Tesla, one should also take into consideration, the drive motor. Since the drive shaft angle is altered from the factory geometry, any abnormalities in the drivetrain could be blamed on the modified suspension.
People always say this, and its sort of true and sort of not. If you do an aftermarket suspension, and then have problems with the suspension, unless the aftermarket suspension is designed to mimic the OEM one exactly, then the manufacturer already has passed the "burden of proof".
The whole magnusson moss thing is about parts designed to the same specifications. not just "aftermarket parts", but "aftermarket parts designed to the same specifications. If you purchase tires that meet the same specifications as the OEM (for example) meaning same speed rating, same weight rating, and same type as offered OEM, then have an issue, they cant deny you.
If, however, you purchase tires in a different size than offered in OEM on the vehicle, or put them in a staggered setup when its not offered that way oem, or put them in a square setup when its only offered OEM as staggered, etc etc, then the manufacturer just has to say "this is not how we designed it", and they have passed the burden of proof.
Any aftermarket suspension seller will also tell people the same thing. Dont expect to get warranty service on suspension issues if you replace your OEM suspension with aftermarket. That has nothing to do with a warranty on brake lights or the computer screen though, and people somehow marry the two together in "void your warranty" as if the warranty on the entire car would be voided, when it isnt.