Received? GrapheneOS are the authors of their software, they don’t receive.

That's how this language is commonly used. "Received" is just in place of what you'd more commonly hear as "gets."

So for example, "Gmail gets new feature that allows users to X" Gmail didn't receive it from somewhere else, but Gmail got a new feature.

GrapheneOS "receiving" an experimental build is linguistically identical to saying "GrapheneOS gets new update that does X"

I agree the article is pretty badly done, but that part I think is fairly normal. Heard that used by all sorts of outlets.

I would recommend going to their Official Announcement and asking the question there or on the linked social media.

They seem to be answering questions on the Nitter/Xcancel linked thread.