To create the Bosnian-Croatian-Montenegrin-Serbian Wikinews, you must go to m:Requests for new languages or m:Language committee/Handbook (requesters). I'm not the right person to ask about this.
Tema na Razgovor s korisnikom:Zblace/Flow
I know what is the procedure, as I already run one project in incubator that was started this way, but my proposal was to start with existing one to see if there is any use and traction, before making even bigger aspirations.
...Let's not use the existing ones yet. You've already made a new one in the Incubator.
Why not? BS is exactly in the middle of macro language spectrum where Croatian and Serbian are extremes.
Serbo-Croatian language and Bosnian language are separate entities. Furthermore, "sh"/"bhs" and "bn" are different language codes. What you were trying to do (to Bosnian Wikinews) may require a lotta coding changes. Moreover, I'm unsure whether another Wikinews site is needed. Wikinews isn't that popular, anyways. Oh, I see: You're running the Serbo-Croatian Wikivoyage, right?
Yes I do.
Indeed SH, SR, HR, BS are all separate, but are part of the HBS spectrum as I wrote above. Why do you think there would be need for any, let alone a lot coding changes, when BS is already a subset in HBS? (note:there are no extra signs in Bosnian and if script would remain Latin only it would be super easy afaik).
I know Wikinews is not popular among many languages, but in this case it is worth trying to do in macro language as it covers more then 20 million speakers and media freedom + capacity is fairly problematic.