> It doesn't take complete blocking before there are significant implications.
Mostly for consumers. Advanced users in e.g. China (likely in Russia as well) use VPNs routinely already.
> from more friction in getting access to distribution channels to the more fundamental "forking" of initiatives and visions
What's in it for the devs/companies to fork just because of the geopolitical situation? A fork means more work, more costs. In some cases, like the Linux kernel, Russian companies (Baikal) are forced to fork, but I don't seem them doing this on a massive scale for projects where they don't have to.
I think there is some parallel development going on in China, but that's more because of the language/cultural barrier and has always been so, so I don't expect a major change.