No, that's properly not a scam. The warning poped up at www.Parrot.com
when I wanted to investigate something about Bebop 2 Power. But what the exact address was, I can't remember. As long as Parrot's own page is not hacked, it's good enough.
Personally I feel it would be stupid to ignore the warning if I had some of the mentioned batteries from the three series. I'm sure Parrot will deliver new batteries to replace those affected quite free when people approach.