Yes, I think that’s a rewording of what I said. As you point out, the word “server” in the title refers to a role, not to a particular device. But that role is, for the writer, something that is already known, so it comes first.
This theme-followed-by-rheme is only a tendency, not a hard and fast rule. In casual conversation, people do tend to structure their sentences that way without even thinking about it. In writing or translation, though, a sentence might need to contain a lot of different elements and, in the process of arranging them, a writer might put the rheme before the theme. Readers might think the resulting sentence seems a bit awkward, but they probably won’t be able to pin down the reason. This “My server is a phone now” title was an exception, because (as the comments below show) some people were confused enough to remark on it.
Servanto, some agent (in grammatical sense, so very broadly applicable) which serves something.
Servisto, some professional serving something.
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That's a big tangential to TFA though, add other noted it suffers from wording ambiguity that don't need any other language to be dispelled. Compare for example "Dæmons dwells on phone now", just as short, far less ambiguity.
The author uses "server" as a role. So "my server is a phone now" translates to "the server role in my setup is now played by a phone".
Maybe this is just a rewording of what you said. You clearly know a lot more than me about linguistics.