That is indeed what is happening. Kinda ruins the feel of gold fever knowing IRL it is found in california hills and in alaska wilds - but in RW it is only found in the south biome. Was much more fun motivation to keep on digging hoping to strike gold in the old version.
It is nothing now but illogical gate keeping.
It's a reason to travel to foreign lands and subject to changes in the future, when more ores and more content arrives