No. But instead of the sophisticated answers, the truth is that the SE management somehow tries to protect the SO as they only can. That the SO is currently governed like a maffia, it doesn't matter for them.
Actually, you could be happy that the vim proposal wasn't deleted long ago. Many similar proposals was killed because "they had been clone of SO".
In most cases there is an instinctual, territorial status quo between the site mods. This avoids most migrations, it doesn't matter how trivial they are.
The SO admins/powerusers hate the other SE sites, because their diamonds / 20k+ repu isn't valid on them. They try to destroy their concurrence since years.
The SE management wants to grow, but they won't conflict with the SO volunteers. Although these "volunteers" long expelled everybody out of them thinking other ways as they are. "Don't change a working system", this is what the SE management follow, and it will be going so until the currently exponential growth of the SE network remains.