Well, if they want to try that they are of course free to try, but the argument has a big gaping hole:
They might not ever change the license terms afterwards for software already on your hard-drive, but they absolutely can do so for updates and likely will. Normally that would result in a fork if the new terms are bad, but who would be willing to fork software under a restrictive non-commercial license that doesn't even allow you to collect donations for running the infrastructure?
So in the end you are basically back at square one with nothing but nice promises by them and still vendor locked.