I think, what you want is a 10mm 1 ply blade.
If instead there was a very thick Ayous core it could be a 3 ply blade. If you take off the Limba top plies then it would be a 1 ply blade.
So, if it had a very thick Ayous core, then it would not be a 7 ply blade.
But, if you understand the properties of wood and why they make ply wood, then you understand, if you had a 7 ply blade, all one kind of wood, and you took a 1 ply blade that was the same kind of wood, the 7 ply and the one ply would play differently. They would feel different. The 1 ply would have more flex. But it would be more easy to break. Which is also part of why 1 ply blades are usually a lot thicker than other kinds of blades.
There are different ways to organize the plies. But, usually, in a 5 ply blade, the grains of the outer ply are lined up vertically, the grains of the medial ply are lined up horizontally and the grain of the core is vertically. So, each layer is lined up at a 90º angle to the previous ply. This makes the blade stiffer because the change in orientation of the grain makes it harder to flex. It also makes the wood more able to handle impact, so, harder to break.
Anyone who has owned 1 ply blades knows that they can be easy to break even when they are very thick because, sometimes, the wood just splits down the grain.
Now, if you had a 5 ply, where the top plies grains were vertical and the core and medial plies grains were all horizontal, that blade would have more flex than the construction I described above.
In some 7 ply blades they do this where they have the core and the closes ply to the core lined up so the grain is parallel. And sometimes they have it so that the ply closest to the top ply and the ply closest to the core are lined up so the grain is parallel. And these patterns would give different feel and flex than the orientation of the grain switching with each ply.
But, the reason for the plies is that adding plies makes the material more durable. In other words, it is the same reason you would use ply wood for anything else as well.