The 89-year-old posted a photograph with his grandson on his official website and wrote, "To my grandson Blanket".
"Be like me: Be tough, be tough in a good way and you'll live a long time". Take care man, be good and I see you next time I come to LA, OK?
The family patriarch also posted a video message on the website reiterating his compliments and urged him to stay off bikes.
Joe said in the five-minute clip: "I want you to stay healthy and stay off those bikes too you know!" You're like your father.
The industry vet expressed a similar sentiment in his rambling video, as he elaborated as to why the Thriller's singer "tried to disguise [him] as much as possible".
'Don't ride none. But anyway, tell your brothers I said hello and stay clean and healthy.
Recently, Jackson's mother Katherine had surrendered her co-guardianship over Blanket.
The elusive teenager - whose mother was an unidentified surrogate - was only 7 years old when the King of Pop succumbed to "acute propofol and benzodiazepine intoxication" back in 2009.
On Tuesday, 14 November, the Jackson family patriarch shared the snap of the risky singer's media-shy teen son and announced that Blanket had changed his name to B.G. or Bigi.
This is published unedited from the PTI feed. I'll see you next time I come to LA, OK?. Above all, I love you all. I don't really see myself as her older brother. Not to mention, it was 20-year-old Prince who ended up in the hospital after a motorcycle accident.
But with the video message, it appears Joe aka Joseph seems a bit confused as he constantly refers to his grandson with his old name "Blanket" and asks him to say his hello to his "brothers".