This is just a VB that caters so specifically to my extremely niche interests that I can't help but love it. From a musical perspective, I think like VBs a la Macne Nana and Gachapin, you could do some interesting experimental and thematic things with it.
I have heard secondhand about people theorizing that Pepper's Voisona VB is Maki's original voice provider, but I think this is likely not the case. I could totally be wrong, but there are a few reasons for my feelings here. First, the voice does not really resemble hers that much. Second, I think voice synth fans are likely to try to draw connections with existing voice synth products, but it's important to remember that this is a product coming entirely from outside the existing voice synth sphere. Realistically, the goal of this product is not to cater to seiyuu/voice synth fans, but rather to make it possible for further promotional demos to be created with the Pepper robot and additional singing capabilities in their voice. It's totally possible a known seiyuu helped create this, but I find it odd they wouldn't explicitly state this if that were the case. TL;DR I feel strongly that this is not Maki.
Anyway, love Pepper.