If you're asking if there's been a diving fatality lately in Belize, I really doubt it. That would be huge news, and this board would be all abuzz about it, especially if it happened at the Blue Hole (shudder).
My guess is that they aren't getting your emails. That's an issue with a lot of dive shops in Belize, and I know it drives them crazy. Have you considered calling them? It wasn't that long ago that a phone call to Belize was like something out of a movie. Really bad connections, echoes, long pauses, etc. It helped to treat it like a two-way radio call and say "Over" when you were done talking. But now it's like calling someone down the street--except for the cost, which is high but not prohibitively so.
Hugh Parkey's been around a long time. And I think they've been doing the cruise ship thing for a long time, too, but I'm not sure about that. In any case, they're almost certainly not going anywhere anytime soon. Their number's 501-220-4024 per the website.
Have a good trip! I'm sure it will all work out just fine.