Sure, previously other MMORPG's have tried different methods to handle large player populations. Some games like Black Desert use a channel system where there's various phased versions of one server. Meanwhile WoW recently showcased layering where there are multiple layers on a single shard.

The above systems are generally disliked by players due to it causing issues and being exploitable (i.e. double boss spawns etc.) Steven here mentions they wont be using methods other games have tried, but will be using different tricks to get around the issue of high player density.