Why would he decide to post ''nour''
To bait people like you in believing that satoshi is back (which is unlikely at this point).
Also another question he added a new friend after a long while, does it make any sense?
It doesn't, maybe it's the hacker's account.
It seems to me that it was a real Satoshi and he showed that everything still exists. most likely this post had some meaning
Yeah it was real just like the post that was made during 2014.