The recent Great Lakes Earth Series has made me wonder, should questions, that share no common name, about a world be linked on meta?
There is no real value in doing so, but equally no harm. If someone wants to maintain the question then if people find it interesting they will use it. If they don't then it will fade to obscurity.
The reason for the cross linking on "Creating a Realistic World" was to link what was a genuine series (questions following on from each other) and a common set of requirements and commentary. None of the others really give that benefit but they aren't causing any problems either.