The odds are pretty high that a hacker made that post. In fact someone on Reddit even said that his email was hacked several years ago because the domain he used went down and someone else took it over.
Yes, satoshi no longer holding including that account (I assume) due to that incident.
Look on what happened next after that post, Dr. Craigh Wright tweeted something about 'light'. LoL
It's pretty obvious that CW is riding the hype on the supposedly Satoshi's cryptic message. But it's obvious that it's not the real Satoshi who has control of the said account. It was breached long time ago so I don't put any weight on it because we all know that Satoshi will not reveal himself with a simple message like that. And LOL at CW using it to make himself relevant again specially after he lost the BCH war.