This is largely due to congress actually taking action in the early 80's, which pushed this date back to the current 2030ish estimate. As the date draws nearer, it gets more refined. If they had not taken action, those previous articles would have been correct.
If congress had done their jobs and done another round of reformation 20 years later in around 2003 we would not be having this discussion now. The date would have either been pushed back or eliminated. It was exceedingly clear what was going to happen back then if no action was taken, and those workers simply did not vote for folks who were going to raise taxes (or reduce benefits) for them. Collectively speaking they would rather have their children pay instead.
From my standpoint the reporting has been very consistent on the subject. It's pretty easy math to report on.
There were amendments in 1977 that should have helped, but the 1980-81 recessions made it bad again; by 1982 the Trustees said it would be insolvent in 1983.
In 1983 the Greenspan Commission and the resulting amendments believed they pushed solvency through the 2050s.
In 2005 that was down to 2041, in 2010 it was 2037, and since then it's sat around 2033-2035.
In Jane Jacobs' book "Cities and the Wealth of Nations" in 1984, she saw the pattern, and brought up that you'd have to keep amending it forever.
There was a point where social security went from surplus to deficit in 2010. That wasn’t insolvency though since the federal government owed them for the previous surpluses they borrowed. 2033 is when the federal government no longer has to pay back money to SS and it is truly insolvent.
You may be remembering that it’s been a hotly debated issue since the 80s.
I distinctly remember it being a massive election issue in 2000 between Gore and Bush (the first election I’m old enough to remember in detail). It was the whole “lockbox” vs government funding of private accounts debate.