Maybe you are misremembering. The Greenspan Commission was the last time we significantly amended social security to avoid these problems, and it was in the 80s: https://en.wikipedia.org/wiki/Greenspan_Commission
Greenspan commission wasn’t a prediction. They used a previous pay as you go model that was simply broke at that time (and had been for awhile$, leading to the current pay for the future model. They then made predictions that the new system would be solvent way past 2033.