I’ve been thinking about the effects of the miasma and Legend since you brought it up and I thinking i have a working explanation. Taylor remembers Legend because she doesn’t have a personal relationship with him. She knows him from TV, news, and forums. The miasma only erases personal bonds. Theoretically, she wouldn’t forget Legend anymore than she would forget Abraham Lincoln or Johnny Depp. Likewise, once she ID’s Jack, she’s knows his power and goals because he’s an (anti) celebrity.
Hmm. I’m not sure the last sentence is true. Taylor seemed to quietly figure out what Jack’s power did when he used it against her, and his main goal of getting to Amy was pretty easy to figure out from the context.
But yeah, the rest of this makes a lot of sense! She remembered the idea of Legend but not her personal experiences with him and, initially, has a hard time recognizing the mask.