Why would it?

To the best of my knowledge, changing software does not cause damage to the TV that could result in warranty being voided.

If the new software burned pixels or did something like that, which I am unsure is even possible from software, then I believe that would cause the warranty to be voided as a result.

But the reason would be pixels being burnt by using the hardware wrongly (i.e. through a bad software). Not merely by installing the software.