About the other shards.

[Brightamethyst]

Could that mean that there is one shard which is really modern due to the time flow differences.

The game already takes place is a very modern world. Just not 'real world' modern.

Remember, Hydaelyn already has a lot of very advanced, even futuristic by real world standards, technology. The reason people still use swords and chocobos isn't because the technology isn't there, but because magic exists to compensate for shortcomings. Guns aren't the ultimate weapons when magical shields and healing exist. Telephones are kind of pointless when linkpearls and other long range magical communication exist. Medical school is mostly pointless when any fledgling arcanist can cast physic, etc. We're already playing in a very modern and advanced world. It just doesn't look like earth.

[JeanneOrnitier]

The game already takes place is a very modern world. Just not 'real world' modern.

Remember, Hydaelyn already has a lot of very advanced, even futuristic by real world standards, technology. The reason people still use swords and chocobos isn't because the technology isn't there, but because magic exists to compensate for shortcomings. Guns aren't the ultimate weapons when magical shields and healing exist. Telephones are kind of pointless when linkpearls and other long range magical communication exist. Medical school is mostly pointless when any fledgling arcanist can cast physic, etc. We're already playing in a very modern and advanced world. It just doesn't look like earth.

You're not wrong but I feel like that's not really getting the point of the OP's question.

As for the question, it's definitely possible that another shard evolved in such a way that it's a more familair sort of modern, only with magic. Like something out of FF15, to use another example in this franchise. I've thought about it before myself. Either way I doubt we'll ever see it though.