No, it's just one person filing a lawsuit assuming that to be the case.
This is priceless. Imagine Wright truly is a fraud. Then he's now being sued by another fraud, and he might have to settle a law suit with real money to avoid the risk of being exposed as a fraud.
It is interesting that it is claimed that Craig and Kleiman are stated to have claimed they were working on a digital currency 6 months before bitcoin was released.
They mined ~1.1 million coins in the early days, and apparently / supposedly agreed to split them in some manner. That's all there is to the story up to now, there's still no significant evidence of Wright being Satoshi. His very poor attempt at previously claiming it, combined with what very much looks like Kleiman's estate being ripped off, rather points in the con-man direction as someone else said.