Well, yes. Strictly speaking, the truly pragmatic approach is indeed to not make language demands, and let things sort themselves out naturally. That is after all how a lingua franca gets established in the first place. Maybe I should have said 'should' rather than 'must'. In all likelihood, this is what will actually happen.
My comment was meant more generally: I strongly believe that in a domain that's as communication-heavy and global as computer software, adhering to a professional lingua franca will yield better results for the field as a whole than having each country write code in their own language, translating only when the benefits of cooperation become obvious.
This has been the case in every (Norwegian-speaking) company I've worked in. Separate documentation has indeed been mostly in Norwegian, but with almost no exceptions, code, configuration and commit messages have been written in English, even though none in the company actually spoke English as their primary language. Ditto for software configurations and OS installs. This has made it painless to search debug messages, ask contextual questions online, get outside help and has ensured zero interoperability issues in libraries and dependencies.
It also turned out to make it almost effortless to introduce foreign-language developers in our teams, a strategic advantage. If we were doing open-source software, these advantages would have been compounded. You don't know what you would lose by using a more obscure language, and the effects compound the bigger the impact your software turns out to have.
Much of this is probably a foreign idea to someone who has only spoken English from birth, but I've seen similar phenomena in other fields that are highly international. E.g. an acquaintance of mine works with biotech sales across much of Scandinavia, and although most people there will be able to understand each other using their mother tongue, using English in common communications greatly reduces the time required to sort out misunderstandings. The access to talent is increased by a multiple, and communications overhead is greatly decreased.
But of course there are nuances to this. E.g. in the case of China, there is probably a developer base in the millions that doesn't know English, and the world will probably be a better place if they are able to contribute anyway. And of course, the laws of physics don't care, it's not like there's some authorization board that will prevent their compiler from working if they do everything in Mandarin.
The domain of computer software will probably move faster if these developers are able to seemlessly communicate with the rest of the world than otherwise. But it's also likely that it will move faster with them contributing with a higher communications overhead, than not at all.