ZirconBlue
Sole Survivor of L-Town
Look up the report. Compare their projections to what actually happened.
2005: 66.0%
2010: projected 65.9%
2020: projected 64.5%
Now, what actually happened? Well, it dropped below 65% in 2010, and in 2015 it was below 63%. So yes, the BLS predicted in 2006 that the labor force participation rate would drop due to demographic factors. But it dropped a lot more than they predicted it would. That additional deficit is not due to demographics, and it's very significant.
Yes, that's discussed in the factcheck article I linked to. I was going to included that section but feared I would end up quoting too much of the article.