According to Google Trends, Design Thinking as a field of study has grown exponentially since 2005. While this graph does not convey absolute search volumes, it does speak to the growth in popularity of inquisitive and iterative problem solving. As this market grows, it will be interesting to see what kinds of new products and services are created to make Design Thinking more readily accessible at scale to the hundreds of thousands of companies who need to approach their problems with a fresh perspective.
Interestingly enough, change management has exponentially decreased.