This is what I know.
There is the different classes.
Voyager was built on September 1977 and was classed as the first of the mega ships.
Freedom was built on 4 June 2006
The Freedom class is very similar design but larger than the Voyager class. Both have these opening windows.
We’ll be going on the Ovation late Feb, it was built in 2016 so it’s a lot newer and a lot bigger.
iirc the Ovation does not have opening windows but I’m sure the window design was not changed because of danger.
I’ll take photos of the pool windows for comparison.
Ovation is a Quantum class ship. It is a completely different animal than the Freedom and Voyager class ships. They aren't a whole lot bigger than Freedom class ships; especially when you look at Oasis class which is a LOT bigger. It's always felt to me as if they built Freedom class as a larger Voyager class, and Oasis class as a much larger Freedom class. But Quantum, Anthem, Ovation and the upcoming Odyssey are all laid out much differently than the other ships.