This one is Bluetooth low-energy, ESP8266 is WiFi. Also the ESP8266 uses an obscure core (Xtensa LX106) whereas this one uses a Cortex M0. So most likely this one is much more energy efficient.
It's a very different use-case than that of the ESP8266.
I say this, because I have devices doing it in front of me. Maybe not for 'years and years', but certainly efficiently enough for long-term sensor usage.
I guess it really depends on how often you have to transmit - if you have hourly checkins the world looks better than if you have to update something every minute or so.
They're using it to describe a short, relatively large transfer of accumulated data collected while the wifi connection is deactivated, and transferred in a sudden stream when it's turned on.