I am trying to understand why a question was moved from ask Ubuntu to unix linux site. The reason given was that site has an answer. Guess what it does not. Many other questions about headsets are presently on ask Ubuntu and it has never been suggested they do not belong there. Therefore I would like to understand the reasoning behind the move.
I assume you are talking about this question.
I migrated it to Unix & Linux because it is a reasonably high quality question that is off-topic here (it's about Linux Mint) but on-topic there.
The migration help text does not claim that the question has an answer, rather that it can be answered on the destination site:
This question was migrated to Unix & Linux Stack Exchange because it can be answered by users of Linux, FreeBSD and other Un*x-like operating systems.
See also the post on Meta Stack Exchange also linked in the help text for further information about migration in general.