I think some of the older models added major features like VRR and such after release, but in general probably not. I’d assume there’s some patched vulnerabilities but if it’s air gapped from the internet I’m not sure how much it matters.

Updates can be worth installing if they solve problems that the TV has (which can be numerous and can vary substantially between models). The documentation associated with a given update should detail what changes it makes and/or problems it corrects.

If the TV is Internet connected then you definitely want to install updates regularly, as they might patch security vulnerabilities.