Which of these are on Gitlab? I assume that’s where they would be(if they are “open source” as claimed),
it could also be possible that /e/ changed their practice in the past and the argument is now invalid(still waiting for a source from them).
However I couldnt find anything regarding verified boot or relocking the Bootloader in the /e/ Docs, which is interesting. Although it seems that in the past there was a section called “Does /e/OS allow for the bootloader to be locked on phones that support verified boot” at least it is recommended as a search term in the docs, however when selecting that there is no direct article.
Also in the Forum it says that:
While here someone apparently got a community build to lock successfully here:
to me this looks like contradictory information, so it seems that some of this is indeed out of date…