Yeah, non-approved doesn't necessarily mean illegitimate. There's almost nothing related to the faith in his predictions, so it's not like someone could somehow get bad doctrine from reading his predictions. He was not silenced by the Church either. But the Church is very cautious about giving approbation to anything, and especially when the prophecies / visions / locutions have little or no bearing on the faith. It would be quite another thing if there was any theological content in the messages. Given that there isn't, the Church probably saw no value in even investigating.