Hydrogen will be very useful as an energy storage solution that can be transported. I don't buy it for this. It makes a lot more sense to electrify rail. It already requires infrastructure, and the destination of rail needs electricity, so it should be part of the electrical infrastructure and trains can utilize that.
Where it makes sense I think is shipping. It's already on the coast, where you have access to water to produce hydrogen, and you can easily load it onto ships to sell to places with an electrical deficit. It also only makes sense when you have an energy surplus.
The issue with hydrogen is it has very poor energy density. Even when liquid, which requires extra energy to cool and maintain and it's still not energy dense. Ship size almost doesn't matter, making it a great option for transporting it. Rail cares about this less than a car, but more than a ship. I don't know if it overcomes that issue.