CCPs can certainly help prevent a reoccurrence of what happened with Lehman Brothers, where, unlike the Treasury, the market didn't know that Lehmans net exposure was relatively small (~$6bn if I recall correctly) compared to the hundreds of billions worth of derivatives it had written, and therefore were scared that if they kept extending credit, they'd be left holding the can if Lehmans went under.

Under the new regulatory regime, a re-run of the 2008 financial crisis would have engendered far less FUD and Lehmans could well have survived. Nobody would have been scared that Lehmans' potential inability would have represented an existential threat to their firm because only the CCPs would have been exposed. (This is a gross simplification but you get the point.)

However, as the article makes clear, the counterparty risk is now all concentrated in just a few CCPs. We also don't know how the market will evolve after central clearing becomes mandatory. The markets have a habit of behaving with a certain ruthless efficiency when it comes to exploiting loopholes or opportunities created by regulation so, like the army that prepares for the last war, the new regulatory regime may not protect against emergent market risks and behaviours.