The community discussed Should we include Conlangs in our scope? a few years ago. It was decided then that conlang questions will remain on-topic at Linguistics SE.
However, Constructed Languages SE is now a thriving community for asking questions on conlangs; there is generally not much point in entertaining such questions here.
We will have to update the FAQ to reflect the change. I'm open to the issue that there could be some kinds of questions on conlangs that are of interest to linguists in general. To help with updating the FAQ, could you please let me know what kinds of conlang questions, if any, could be of interest to linguists or the Linguistics SE community, rather than the Constructed Languages SE community?
By default, I'll update the FAQ to indicate all conlang questions as off-topic at Linguistics SE.