For OT alone it would not matter, it already has to manage the memory and loading of the assets and terrain in a way that doesn't require an extended address space. However, games and simulators built atop of it simply boost the usage of the physical memory, and the address space associated with that memory is always larger. And given that there's also the embedded browser running within the same process space, it can easily happen we run out of the 32 bit address space in case of some memory leaks caused by lazy evaluation and generous allocation of memory chunks within the browser, for example.
But even if all the memory allocation was tight and everything behaved correctly, because the OT world scale also enables large scale apps, some of them are simply going to hit that 3GB usable memory limit.
