>Unless the options grant had specific language of an expiry period I would gather there's a very good chance of a large payout

You're intentionally trying to muddle the waters here by arguing along two different axis.

1. the contract granting options has a delivery period (in your words "expiry period")

2. the options themselves have a duration (aka expiry period)

When you are saying "Unless the options grant had specific language of an expiry period" you are only talking about the delivery period of the options. Aka when the options become available. So you are not complaining about late delivery, you're complaining about lack of delivery.

When you are saying "I would gather there's a very good chance of a large payout." you are intentionally confusing (1.) with (2.). The delivered options have a value on the open market and that value was not delivered. Hence there is a contradiction. You're saying "large payout" but the options are only worth a fraction of the shares at the time the issues vested. You do not get to simulate the most optimal future that you would have exercised the options and held them for thirty years, you have to prove that yourself and the best time to prove that was 27 years ago aka within the statue of limitations. Now that 30 years passed, you have to argue that you would have held the options all the way until today and exercised them today, but the grant only covers the option premium at the time of the grant, not the option premium of a 30 year long option. So Nvidia can still give you your options but the options would give you the exact same duration as the options back then and you would get exactly the same premium on them.

Basically you could make Nvidia the offer to settle for the value of the options so that you stay quiet and don't sue them, that's what your lawyers can get out of that contract.

Edit: Correction with regards to how big the payout can be, can be found here https://news.ycombinator.com/item?id=49874789