I think there's a major misunderstanding of Watson which isn't helped by IBM's Marketing efforts. IBM Marketing has been slapping the "Cognitive" label on everything and is creating unrealistic expectations.
The Jeopardy playing Watson (DeepQA pipeline) was a landmark success at Information Retrieval, its architecture is built largely on Apache UIMA and Lucene with proprietary code for scaling out (performance) and filtering & ranking. I'm not an expert on IR so I won't comment further. This is very different from Neural Nets that are all the rage in ML today.
I'd like to point the following links from David Ferrucci [1] the original architect of Watson and this technical publication at aaai.org [2].
The DeepQA pipeline wasn't fluff, the intention was to take this question-answer pipeline and apply it to other verticals such as Law and Medicine, essentially replace the Jeopardy playing Watson's corpus of Wikipedia, Britannica etc... with Legal and Medical equivalents.
Given its runaway PR success, the Watson brand was applied to many other areas which haven't been successful but I'd like to point out what the original product was here.
[1] https://www.singularityweblog.com/david-ferrucci-on-singular... [2] https://www.aaai.org/Magazine/Watson/watson.php