It has nothing to do with the 21st century - if most of a dive ops customers will have yoke regs, it makes sense for them to have mostly that. Yoke is pretty much the common standard in the Caribbean (and quite a bit of the world, actually.)
You need to check with the dive ops you are interested in. You will probably find some hybrid valves and you may find some regular DIN valves. I'd speculate that the more an op markets/caters to European divers, it's more likely they will have more DIN valves available. But I think if you use a DIN reg it makes sense to take an adapter when you are traveling, just in case.