It does. They obscure the usage of non-free hardware/firmware by not shipping it as part of the OS, but as a bundle on separate flash storage that is loaded into the OS by initrd. That blob is updatable as "firmware". The 100% free open-source is just marketing. It's just for the OS. A lot of the hardware and firmware is proprietary.

https://github.com/linuxboot/heads/blob/c859c28b88b7bc197c16...

https://forums.puri.sm/t/the-librem-5-blob-list/28815/26