Can one expect the patent examiner to know that an 'IOT sensor' is a sensor that communicates to a computer that is networked into a LAN or WWAN?
No one here can answer whether a future examiner will be familiar with a given term. There are so many examiners which such a range of knowledge and experience.
However, the fact that you are asking the question suggests that the term has not reached the point that an examiner (let alone the person of ordinary skill in the art) would necessarily be aware of it. In such a case, the prudent thing to do is to include a definition in the description. Because what is the downside of doing so?