It seems very unlikely to me. I've had personal correspondence with Satoshi, and met Adam Back in person, and I can't see it.

Actually I don't see how anyone involved with Blockstream could be identified as Satoshi. They never believed in what Satoshi was doing and built their whole company around the claim that Satoshi had screwed up the core of the system's design, despite that nothing about the design or its assumptions had changed. They spent years raising investor capital (why would you do that if you were rich?) specifically to build a system designed to replace Bitcoin for end users.

The last time I met Adam he was trying to convince me to not continue working on Satoshi's original design, and none of his arguments were technical. Satoshi had a totally different approach.