Anarchism is primarily a western ideology, but has existed long enough at this point to be a real material force in western society with arguably more influence than Marxism (probably not, but at least culturally it is). In a post-capitalist society, it may be necessary to collaborate with them in reconstruction at least in the short term. This goes without saying, but knowing what the future holds is impossible and there are many possibilities. I think most likely BIPOC nations will need to subjugate settler populations for a period of time making this idea of collaboration pretty much irrelevant, but I also don't want to discard the possibility entirely.