From Reddit and the Ask Riot section of the League of Legends website we have a couple of new pieces of information about additional regions for Legends of Runeterra.  We've currently got 6 regions (Freljord, Noxus, Ionia, Piltover & Zaun, Demacia, and The Shadow Isles) and several existing ones in LoL, such as Targon, Shurima, Ixtal, and The Void.  Which region are you most looking forward to seeing?

Quote From Riot AlphaLvSim

Just checked with folks, and yeah, can confirm that set 2 will add a region

From the "Ask Riot" post someone submitted the question "Are you going to add new regions to Legends of Runeterra? What about champions who aren’t from any region, like Fiddlesticks? Does that mean they’ll never be in the game?"  This is what the Game Content Product Lead had to say.

Quote From Riot Dovagedys

Yes! We’re definitely going to add new regions to Legends of Runeterra.

When it comes to champions that historically haven’t been connected to a specific region—we don’t use that as a restriction when deciding which champs to include in future releases. In Legends of Runeterra, we need rosters of champions to fit within each region, but some champs are more flexible than others when it comes to where we can potentially assign them. For example, Garen or Jarvan IV are more restricted in that they are both Demacian, “now and forever.” But champions like Teemo, Riven, or Tahm Kench are far more likely to wander throughout different areas of Runeterra. We want to use that variance to ensure every champion can find a spot on a roster. We have the most flexibility with champions that haven’t been commonly connected with specific regions throughout Runeterra, such as Fiddlesticks, Brand, Ryze, Annie, etc.