I also wonder how one might go about changing the OS. Would it support live-USBs via OTG? or booting from the microSD? Do they offer an ISO of PureOS to reinstall? I wonder how difficult/easy it would be to do a normal Archlinux ARM installation, like on any other computer.
The marketing seems to focus on privacy, and being fully open source, and buying for the community benefit of promoting better tech in the market. However, if it's a "linux phone" that can run any linux app and even easily lets you run whatever distro you want, then there are practical, personal benefits to buying this, too. It wouldn't be instantly obsolete like so many people are saying.
And if the window manager and phone apps they made are distributed separately, then one can install their favorite distro, and install those programs, getting the same look and usability on their favorite distro.
I only found this secondary-source article[1] from a couple years ago that says it would support booting most distros, but is there anything official?
[1] https://www.cyberciti.biz/linux-news/the-librem-5-your-ultim...