One thing that stuck out to me in the article is that they only mention one meaning of "huh". As you have pointed out, there are multiple meanings of "huh". You have "huh?" meaning "I don't understand, please repeat and clarify". There is "huh???" for "express soft skepticism or disapproval". And "huh!" for "express soft surprise or shock". Or "huh." for "express that I didn't realize something". Even "huh..." for "I need to think about this more".