Is it possible that we have a migration website, where users could post questions irrespective of the topic of their questions, and the community would migrate them to the suitable stack exchange network?
On Meta Stack Exchange, there is a site-recommendations tag (see here). A user can post a possible question (or a description of a possible question) and ask for a site recommendation for the question. Members of Stack Exchange can give feedback and help the user put the question on the correct site.
This proposal would be a duplicate of that feature.