Irony is he will probably burn more shorts with this announcement than he did with the initial set of tweets... and the SEC helped him do it this time around!
Social security will always be around in one form or another. Despite the fact that many Americans detest the idea of a welfare state, we're still collectively bright enough to realize that you can't simply leave no options for the sick, poor, and disabled.
The better question to ask is whether you will be happy living out the twilight of your life on a government controlled amount of money. This amount will likely always gravitate toward the prevailing poverty line. Unlikely to lead to a truly comfortable existence. Definitely not enough to live in any high COL location. Average monthly benefit in 2017 was ~$1,300, and MAX was $2,687 [1]. ~$15-$30K will cover the basics in most lower COL parts of the country, but not much more.
Sounds like it's time for a change to the state constitution. Everything is a negotiation:
"Because the state’s constitution bans any reduction in worker retirement benefits, the government’s pension costs will continue to rise as it faces pressure to pay down that debt, a squeeze that has pushed Illinois’s bond rating to the precipice of junk."