Well, it does fit in with reason #2 from my previous post. The point of that reason was to show how tedious creating the hack will be.
Cobalt Blue project was started in 2006. The last update announcement that Blazichu, the creator, made was around 2008.
During that process, there were high amount of bugs, crashes, and glitches (such as no Wild Pokemon appearing), in the attempt of creating more regions.
Yes, Blazichu did promised Kanto, Johto, Hoenn, and Sinnoh, but as of now, Kanto and Johto regions are the only regions that are properly working(Since it's from the original Gold ROM).
Sorry to say this, but those kind of hacks are something that might not be accomplished.