This is a legitimate concern. As part of the licensing agreement to be called a "Firefox OS phone" I believe carriers must provide updates for a certain amount

This is a legitimate concern. As part of the licensing agreement to be called a "Firefox OS phone" I believe carriers must provide updates for a certain amount of time. For how long, I do not know. If the duration is public knowledge, I do not know. If partners will actually follow through, well... the articles you linked to paint a bleak picture. Of course, since our entire OS is open source, they can just use it on their own, and never release a single update, as long as they don't brand it a "Firefox OS phone." I'm prototyping an add on right now that would detect a connected device, download updated pre-compiled images of the layers (gonk, gecko, gaia) and allow you to update them (if I verified that the update worked on your device beforehand, to make sure you wouldn't end up bricking your phone). Just trying to raise awareness within the org right now to get a green light to work on this more.