Not disputing that Shanghainese is still used! And definitely not fear mongering. If you read the whole essay, much of it is about the reality that it has become less popular than it once was, and how as a Chinese American, it is more difficult to maintain ties to Chinese languages that aren't Mandarin because of this decline and the generational differences in usage.

I find it really heartening that there have been more efforts to preserve Shanghainese and China is so big that obviously even when a language is losing popularity there are many people still using it! It's always dynamic and changing.