Pretty much. A similar approach of only unsolicited advertisement packets is used by a number of beacons. But that is not the only use case. A decent number of BTLE sensors out there also work exclusively by periodically sending out unsolicited advertisement frames with their data.
As long as you don't need to accept any incoming data, that is really easy to do, and allows completely shutting off the radio in between, so the radio may only be active for a few miliseconds once every few minutes. That helps keep power consumption very low, especially for battery powered devices.
If the primary sensor functions are low power, and support an interrupt signal, and you have a microprocessor with a low power timer interrupt (to allow waking up occasionally even if the sensor state has not changed), and ability to stop the clock to the rest while waiting, you can pretty easily get multiple years on a single disposable AAA or coin cell battery.
Over the summer I bought a RaceBox Mini, thinking it was a fancy GPS logger, but instead of logging it broadcasts the current location over BLE whenever there's a device connected. RaceBox makes an app, but since it's standard BLE I was able to write a systemd service that runs on a RPi and logs to a SQLite database. A lot of the standard BLE interfaces have built-in support in Bluez, so it was pretty easy to setup.
"Beacon", as in "attracts attention to a specific location"? No, not necessarily.
You could use this to broadcast GPS coordinates (and you can always try to triangulate the location of a BTLE transmitter), but the author is showing what he believes to be the simplest way for an embedded project to transmit arbitrary digital data over the air - to, for example, an iPhone.
Beacon has a pretty specific meaning in the BLE world. A BLE beacon sends a broadcast out every now and then* that says “hey I exist, here’s my ID”. Another device can scan for these “advertisement” and do something when a particular kind of device is detected.
An example use case is a museum app displaying info to a user when they walk up to a particular exhibit.
* the interval can be set from 10ms to ~10s. The radio can be turned off in between advertisements, which is where the “LE” part comes from.
Pretty neat!