In the article you referenced, the author distinguishes M2M from IoT largely on the basis of the types of networks they connect to -- cellular for M2M vs. something new for IoT.
In that sense, both articles seem to be saying much the same thing -- that the cellular networks are not optimal, either technically or economically, for the billions of "things" that will be communicating with each other, without human involvement, in the coming years.
Funny that the same issue has an article on how M2M is giving way to IoT:
Now, IoT does split the whole thing into 'dumb pipe' and some value-added services, where telecom companies have to compete on even terms with everyone else---and telecom companies don't have the best track record in this area. As a random example, Verizon has an app, MyVerizon, that is supposed to be a service portal for their cellular customers. The app is atrocious and is universally panned by users.