To answer the original question : no! that’s definitely not right. I’m not even sure where you found that link but that’s just a search in the commits/review comments for the word ‘purism’, that’s not an actual build or image or even a tree to compile from!
Like @Caliga said, the official way to update coreboot is to use the script for which you can find a link and instructions here : Building coreboot from source (official script)
The reason you’re not seeing “update on the machine” is because if you’re using PureOS, then for that distribution to FSF approved, it cannot have any non-free packages and while coreboot itself is open source, it depends on binary blobs from Intel to initialize parts of the hardware. That’s why coreboot distribution has to happen “out of pureos”.
As for your last sentence, I don’t understand, are you saying your machine was shipped without coreboot? that’s extremely unlikely (unless you have the v1 models which is not possible since you said you bought it in 2018).
@Amarula the factory installed coreboot is usually updated on the same day that I update the build script for everyone, so in theory, if you bought a librem today, it would come with the latest update. Sometimes though, it can take a little longer because machines might have had coreboot installed to them in batches or because the tech in the factory hasn’t updated his USB stick with the new files or any other reason like that.
@Caliga: That wiki is for Pureos, the real ‘purism wiki’ would be at wiki.puri.sm and the coreboot related page would be : https://wiki.puri.sm/fw
I admit to not actually updating/caring about that page so much. It’s a wiki though and it was mostly supposed to be maintained by the community, but I don’t think the community really knows about the wiki (it is pretty recent).
Yes, you don’t really need to update, unless a feature is interesting to you. Usually, as long as the machine boots and works, that’s all that matters.
We are working though on integrating librem support in fwupd so people won’t need to keep checking the forums, they’d get a notification if an update is available. Hopefully that will resolve most of the issues (the build script was really meant to be for internal use, but it ended up being the official method for users to update too).