By using the word "obsolete," the communicator is being--intentionally or unintentionally--intellectually shallow. Even if the word serves their purpose, they are also wrong in a big way.
The fact is, this machine still does what it started out to do, technically speaking. If you look up the dictionary definition of obsolescence though, you'll find some really terrible news: "no longer useful." An Atari 800 is no longer useful? That's arguable, to say the very least.
The best way to communicate obsolescence with accuracy, precision, and rationality is with a reference point, like a market: "This tool no longer serves its original target market with the efficacy that it once did." This is much more precise. However, it opens the door to another depth question: Which markets or sub-markets might it _still_ serve, and even speak to rather loudly?
IMO the discourse of obsolescence is a curse on modern civilization. We are missing out on some huge _qualitative growth_ lessons until we learn to think in a more nuanced way about how technology serves us all.