One thing I do wonder about now though is since vocal synths are gonna be all split up is how much harder is it going to be to acquire them and use them together if they’re on different programs? Like V Flower will be a Cevio while AHSloids are moving to SynthV and then there’s of course Piapro studio with NT. The major benefit of the vocaloid engine is that it was a central hub of all these different companies but now there are like 3-4 different softwares with different ways you use them. I don’t use any of these softwares so maybe they’re all very similar but I just see that being an inconvenience that will arise from this.
That's true, though as long as the old Vocaloid software keeps working, it won't be something that needs to be addressed all at once. And I'm not sure exactly how much different this will be from how it was before.
It seems like we're losing out on the interoperability of the different Vocaloid libraries, under the assumption that they're moving to one of the current major singing synths (Vocaloid 5, Piapro, CeVIO, and Synth V; there are some other synths, and I don't mean to impugn them, but my impression is that they're not as big as the others). But in that move, we're not really gaining new barriers so much as making existing barriers apply to more synths, because all of these synths are basically upgrades to platforms we had already.
It's true, though: depending on which voices you like and would like to use together, a person may have to learn to use multiple engines.
The good thing in all this is that the above engines are still joined by two common languages in terms of their phonemes: X-SAMPA and arpabet. Vocaloid 5 and NT use X-SAMPA, and I believe CeVIO and Synth V (at least the current ones) use arpabet. So if you had reason to make synths from different engines swap phonemes, it's possible to do so if they share a common language. It should even be possible to translate between them, too;
@uncreepy made a
chart that does just that, at least for English.