A ¨weasel word¨is a new concept for me. I don´t recall ever hearing it before.
I've heard and used the term 'weasel word or words' for ages. I can't remember the first time I heard it but it's been decades, I'm sure.
Interesting. Not sure what to make of this. Do both of your states have weasels? 
I have to agree with Susan. I have never heard that expression „ a weasel word“ in my life.
If Jerry has heard it before, I have to suspect there is a regional aspect to it. Neal could give you the New York perspective.
I can guarantee you if you used the phrase „weasel word“ in California, no one is going to have the slightest idea what you are talking about.
I‘ll have to ask my mom about it. She’s 91 and has lived in California her whole life, with a few exceptions of living in a few other parts of the country when she was younger and we were all much younger.
She might surprise me and say she knows what it is. She`s surprised me before with some words, like „truck patch“, a word no one uses anymore.
If that is the case, then I would put the phrase in the „aged“ category (what we call in German, „veraltend.“ Not totally dead, but rarely used“. Not quite archaic yet, but moving in that direction.
If she’s never heard it, then it has to have only some regional use.
It’s a good expression, from reading the Wikipedia article.