Here's my take on the whole issue of stuff being released or not.
Tamashii doesn't create figures just to display them and not release. It costs money to make each and every prototype and they display with intent to gauge interest and ultimately sell. The ONLY figures that they've shown and haven't given a definitive update on is Nappa and Shenron. Here's why. Nappa was revealed long ago but wasn't very well done because they were still trying to figure out how to articulate large characters. Plus he was nude so the joints were very obvious and fans didn't react too well to him. They then decided to put him on the back burner. During this time they figured out how to fix the mistakes made with Nappa. A short while later, the first large character, Broly, appeared. After sales for Broly exceeded their expectations they probably continued to work on Nappa, most likely with armor. They know the demand is there and they even acknowledged it. He WILL get released, eventually. Key word is eventually. When it comes to Shenron, he's obviously a very large character so the price is gonna be higher. That one is obvious why they don't want to put into production. It's the riskiest prototype they've made.
Now for the Buu's. SSJ4 was gone for a while because they took him back to update him with new knee joints and add the finishing touches. Now we see him ready to go. The Buu's are experiencing the same absence. They had the same old knees from before and now Tamashii is likely adding the new joints and finishing them up. We'll probably see them late this year or early next year, ready to go. They actually WERE seen earlier this year along with Shenron too.
In summary, Tamashii has released 95% of what they've shown. That other 5% is Nappa and Shenron. Not actual statistics, just painting a picture. The only updated of those two is Shenron in that he was last seen at the same event the Buu's were. Still even though he was shown, I don't think he'll get a release, at least not now. Same goes for Porunga. So it's only been 2 figures that they haven't released (4 if anyone really thinks they simply scrapped the Buu's). Obviously this doesn't count the new stuff. Out of the new stuff, the only one I think they won't release is Angel Goku. Even that one is still probably gonna get released.
Oh and I didn't forget about Jaco. He's definitely coming out too but they just haven't been displaying him. He's most likely gonna be in DBS as a regular character so he'll come out eventually.