My impression was that the Ross family guarded the rights incredibly closely and will only license his likeness for artistic supplies and so on. They also frown very heavily on people sharing even the best, most uplifting clips of his show to YouTube and can be pretty litigious (which is why all you can find on YouTube anymore is mean-spirited fratboy-humor parodies).
Apparently this ad has been around for a long time, and nobody knows if the Ross estate did anything about it (or whether they were paid for it or not):
Interesting. I always sort of assumed it was the opposite. It's probably on here somewhere but I'm reminded of the MTV promos (this was the only one I could find)
that I believe aired for a while after his death. He's a universally recognizable TV artist, especially in a Foreign market: off the top of my head I can name/recognize exactly one Eastern TV chef in the same way I could recognize Bob Ross even if I didn't know his name. He's the Happy Trees guy the way that Morimoto is the king of the Iron Chefs. I don't see this as offensive in the same way as reanimating Gene Kelly or making a CGI Orville Redinbacher; it's just his picture coming to life to promote some smartphone using old footage.