EDIT
I have streamlined a bit my original question, now it should be clearer. The very helpful comments that convinced me in opening the present question are here.
This question (which is not mine but only contains an answer of mine) have been migrated from aviation.se to drones.se.
According to this Community wiki: "It is perfectly possible for a question to be a good fit on more than one site. It is also possible for a question to be a better fit on another site than the one it was posted on. However, those are not reasons to migrate it elsewhere, unless the author specifically requests it. As a general rule, if someone asks a question here, and it's not a bad fit here, it should stay here." (emphasis mine).
That wiki also report the following diagram which, applied to this specific case, brings to the orange box (i.e. if anything, to the deletion of the question):
So my question: is this particular migration correct?
Furthermore, on aviation.se there are many other questions (like this one, or this one or this one just randomly chosen) related to drones or model aircraft which have not been migrated/questioned/deleted/closed even if they have nothing to do with aviation.se: why are they still there?
Please understand that I truly do not care where that (or any other) question (or answer) should be: mine is just a basic process-related doubt.