Am I right in saying a Master Pentultimate will also be made before then?
Might it be that you are referring to a post that is somewhere in this forum where someone said that the Pentultimate is a bandaged version of the master Pentultimate?
Because I recall that somehow and never really understood.
Now I don't know anything about designing mechanism. I only always take my bought puzzles apart and try to understand how it works. (At least with most of my puzzles.)
But I think when comming from the Starminx there is no reason why the Master Pentultimate comes first.
I got the idea that you can imagine it like a Master Skewb: Look at the mass produced version. It's not a buildup with added functionality to a normal skewb. Instead there is a Dino Cube inside and the edges are connected to it.
You COULD however also make a Master Skewb from a normal one by adding layers. I think that's how Drew made his higher order Skewbs.
So I guess there is another way to approach the Master Pentultimate too. One that is not build up on the normal one but somehow recieved on a different way. I can't even close imagine what that could be. In that case the normal version would be shell above the master version.
I still believe that when comming from a Starminx though, the Pentultimate is a shell that comes before the master version.