You would assume they would. The slims sold really well so I'm going to guess they will be pushing one out around new years.
The Slim seems like a different beast to me. Quite the refined/specialty kendama if you know what I mean? It is possible that they'll make a plus slim, but I'm thinking the slim may ONLY live in the "craft" space. Seems like that kind of kendama. There is a reason the other is called "2.0" and is showing up with silk paint, bamboo, plus, etc. Of course this is all speculation on my part, I really have no idea.