I don't think so.
Any soft collapse will include a mass migration/expulsion of peoples.
There are more ethnic Baluchis outside of Baluchistan than inside. Do you think that this Pakistani "rump" state will tolerate their presence? I don't think so.
What about the Pakhtun population in Karachi? Surely there will be warfare there.
Also you can't just assume that Baluchis and Pakhtuns will be in the same boat. Although culturally and socially we might constitute a larger nation, more so than Punjabis, and Sindhis, I see additional conflicts ahead if independence was a reality.
I think that Pakistan has done a poor job with respect to Pakhtunkhwa and Baluchistan. Eventhough I support Pakistan to the fullest, there is that element of marginalization, questioning of patriotism, and the massive amounts of ethnic slurs/hatred that is freely espoused by many Pakistanis. The Baluchis are in much worse shape with their voices going unheard.
Ethnic minorities and diasporas have seldom come in the way of the aspirations of mainland communities. We have so many examples in history. There are as many Muslims in India (if not more) as in Pakistan but Pakistan came into being on the basis of a separate homeland for Mulims. Why not look at China (Chinese all the way upto Indonesia), Russia (Russian minorities throughout Central Asia), Tajakistan (Uzbaks), Uzbakistan (Tashkand is primarily a Tajak city), etc.
Yugoslavia itself is an example. There are serbs in Bosnia-Herzgovia, Bosnian Muslims in Serbia, Croatians in Serbia, Serbians in Croatia, etc.
In these circumstances, UN charter, international norms and conventions, and state responsibility come in play to protect minorities.