I'm not quite as sure. To me, its kind of like saying "well, we don't have to worry about global warming, oil is awesome and if it gets too bad we always have Mars". Which, I can explain a little bit because that analogy maybe only make sense in my head.
I can't think of very many, if any, examples in computing history where a project, open source or not, followed the path of "dominating a domain" -> "sponsor does something crappy" -> "the community rallies around a fork" -> "the fork becomes a dominating force in its domain". I'm really sitting here trying to think of examples to help disprove this thesis, and would love to hear them. LibreOffice may be a good example. I can also see an argument for Oracle/proprietary SQL vs MySQL/Postgres. The NodeJS/iojs situation from years ago is, I think, a hallmark case-study in open source that more-so skips the "rally around the fork" step, but is nonetheless worth mentioning. There's probably dozens of examples in the "random esoteric npm library" domain, but those aren't hitting a thousandth the scale that the gigaprojects like VSCode do.
There's a far more common path for projects, however. I'll pick on MongoDB as an example; they did something kind of crappy, with their GPL-wearing-a-trenchcoat-proprietary license which, in my experience, all but killed the database for some companies I've contracted with. These companies (users) took that opportunity to move to a truly open source solution, like MySQL. The move, in all cases, was long; arduous; cost a lot of development time; and they were happy in the end.
Circling back to the metaphor; there's a hypothetical migration path for anything. Its near-laughably trivial to even list that as a triaging factor for "well, they could be evil, they could turn evil, burning oil could destroy our planet, but at least we have Mars." Computers are turing machines, anything can be rebuilt. That's not the point. If we opt in to an environment which is only deemed acceptable because of a Plan B, it behooves anyone with investment in that environment to think critically about the probability of being forced to implement Plan B, and the cost of that implementation.
Circling back to the examples: one is behooved to analyze this through the lens that Plan B may not be the Plan B one thinks it is. If VSCode jumps the shark; will vscodium take its place? MongoDB jumped the shark, and no one was there to catch it; those people who were left wading in the water had to invest significant engineering time transitioning to something entirely different. VSCode is more than just Code; its the users, its the marketing, its the trademark, its the extension standards, its the governing body, maturity, maybe even patents, its all these things which vscodium does not have.