This is one thing I've struggled to understand.

Scenario A: RSUs have an expiration date. RSUs you own expire before the company hits a liquidity event.

Scenario B: RSUs do not have an expiration date but the company goes bankrupt/dissolves and never hits a liquidity event.

Is one of these scenarios taxable and the other one not? One of my biggest fears about joining a startup (pre covid) was scenario A happening.