LINUX is a open source operating system based on a Unix-like kernel that is already available. Steve Jobs built OS X on a descendant of Berkeley Software Distribution (BSD) that was based on Research UNIX. It's not like Huawei with its enormous resources would have to pioneer something entirely innovative to be competitive. It would even be possible to develop an Android alternative.
What about chips, you say. Well, it's not like the budding Russian-Chinese alliance can't or won't develop a competing chip industry. No doubt this has already been in the works for some time, since both Russia and China know their tech vulnerabilities.
Google knows that and is concerned enough to lobby the Trump administration against attempting to isolate Huawei and by implication other Chinese technology companies. Google is using an argument based on national security in this regard, but but the subtext is that trying to use anti-competitive policy against China is likely instead to increase the threat of Chinese competition by forcing China to become self-sufficient and independent of the West, just as US sanctions have forced Russia to adopt import substitution.
It doesn't look like POTUS has sufficiently thought this through, especially knowing that China is a long hauler whereas Wall Street is quarter to quarter.