DJLippy is sound. She's also a Mumsnetter if I recall.
And she has been relentlessly targeted by TRAs. She will be fully alive to all their latest wheezes.
And people do get sucked in. Something looks legit, sounds legit, they want to help, they join.
She's just pointing out not to join any WhatsApp groups unless you are absolutely certain they're kosher.
And whereas most people might be fully aware of that, there's about to be some that aren't.
edited to add that there's no downside to being careful.