I'd argue that it is not possible to have an end. Culture and society, like species, continue to evolve and is never a static thing (believing otherwise is one of the big contradictions of neolibs and other staunch pro-capital ideologies). So, "post-communism" could be a set of philosophies that may not be concievable until such point that humanity has evolved culturally and socially enough. Possibly influenced by technological or external factors.

The nature of the dialectic is for it to continually and fluidly evolve, every now and then contradictions mount to a point of qualitative change and give rise to a new system that resolves the contradictions of the last, but gains new ones. It never ends. Marx only said, capitalism will bring about socialism, which will in turn bring about communism. Everything after that is too far away to really make any concrete statement that isn't grossly biased by the conditions of our time.

Fully autumated luxury space gay communism, comrade

If you aren't joking, they mean 'to post the propaganda on the Internet' and not post-communist.

Star Trek is what comes after communism