As much as I wouldn't hate for JP voices, I feel like their reason for not bringing in those voices are for two reasons:
1)They'd need the permission of the VA in order to use it, especially collab ones where they'd need to have the licence for things related to a collab, including voice tickets.
2)They may (or may not) be waiting to get English VA's in order to release those tickets. There is an option to search for Voice Tickets in the Visiphone, so I want to say that we'll probably will get them, but it'll be a while.
Honestly, my best guess is that we may get some collab VA's, but if we do get Voice Tickets, we'll most likely just get NPC VA's, which is still underwhelming compared to what JP has.