It doesn't matter what Rails decides to do if your HTTP server doesn't support it.
With that said, it looks like many do already support it (from the same article you linked): Apache, nginx, Phusion Passenger, Unicorn, Thin, and WEBrick.
Also, Rails supports an override as well, so you can send it as a POST but specify a different verb in a header, and it will treat it as a native request with the correct verb.
With that said, it looks like many do already support it (from the same article you linked): Apache, nginx, Phusion Passenger, Unicorn, Thin, and WEBrick.