Are you talking about God Eater here? (I don't really know if that's a hunting game or not )
Anyway, I presume it's simply because that's where the fanbase is. Also, the PS4 version of God Eater: Resurrection will make up a much bigger portion of total sales than the PS4 version of God Eater 2: Rage Burst, so it does suggest that the fanbase is migrating.
This doesn't show migration at all.
If this is a showing of migration, than its completely destructive and unsustainable.