"For now" because they are making it harder and harder to do it, and so, it's not a stretch to imagine a day where you simply can't do it. Or you can, but it will be rendered meaningless. For examples, look at how hard it is on phones to change the OS and even then, we're at the mercy of the AOSP remaning open and up to date. On desktop, Secure Boot is yet another wrench thrown into general computing. Or, nowadays, how do we really separate two browsing sessions? A private window is a good shot, but still there's ways to connect that to your normal browsing session.
The protocols and methods that can make the current ecosystem free feel like holdouts from a world that's passed already. I really really wish that the future is not closed, that we can still host our email and websites in 50 years, but when all key players want a closed and surveilled ecosystem, it's hard to imagine that remaining open is not a struggle.
Hence, "for now".