Perhaps cognitive science failed to move from a "collection of multidisciplinary efforts to an integrated coherent interdisciplinary field" because there was not a high demand of this interdisciplinary field. However, there may be a higher demand to study cognitive science because the public, media, and scientists have expressed greater interest in developing artificial intelligence over the years. Similarly, younger generations like myself are becoming more self-aware, constantly asking the question, "are we just living in a simulation? Is anything truly real, or real based on our perceptions?" I think the training in cognitive science will become necessary for the new generation of scientists due to the increased demand of developing AI's as well as studying the human consciousness (i.e. our extent of free will).

Maybe this prediction hasn't been fulfilled because cognitive science is so multidisciplinary, and the newer generations of scientists prefer to study disciplines in the hexagon because they are more broad and therefore have more funding/faculty support. Since multidisciplinary fields are so specific, they may not have as many students, faculty, nor resources which is why these fields don't transcend their "founding disciplines."

overall summary of the data in Fig. 2

What does this mean?

Interesting. Who (or what) would threaten the field of cognitive science?

While this is true to an extent, it's important to note that cognitive science shouldn't solely be associated with computational machines (i.e. artificial intelligence). When I think of cognitive science, my mind associates it with the human mind (i.e. psychology) rather than computation.