I agree that throughout the article, she continues to signal in a way that one would signal on IG or FB. It’s offputting because she seems to miss the point of why social media can be unhealthy.
I'm afraid I'm bad at reading between the lines -- what sort of signaling is she doing in the article?
She is signaling her virtue by leaving those platforms, just like social media promoters signal their own virtue in other ways (diet, exercise, food pictures, stories about how awesome and relaxing they are at child care, etc) on those platforms.