Sometimes an artist or writer will leave/quit/get fired, only to suddenly return a few months later because things smoothed over. While working with Vanadis, it wasn’t unusual for the next game Bubudzuke was working on, to be released 10+ months later. So the one year drought could be ordinary situation. I’d argue to wait until 2015 goes by without a Bubudzuke title released by Vanadis, [u]then[/u] it would be “safe” to claim he’s left them for good.
What is unusual, is that Bubudzuke gone to other studios for work… so that’s worth a bit of concern: his work pattern indicates he’s “dedicated” to the studio he works with, unless he leaves them.
Again… it’s been almost a year since Vanadis released a title with his art, but that also happened with Sei Monmusu Gakuen. Perhaps there’s another title in the works for 2015. But if 2016 arrives without anything from him with them… I’d say it’s totally over.