If that was all lip syching the other day, it wasn't to the studio versions. I have listened to Folklore and Evermore enough now to know that those vocals were a little different. Certain inflections and tones were not the same on many occasions, so it is possible she recorded a fresh take of each song in the medley and then sang along to that backing track and it is possible she did lip synch to the fresh take. Doesn't take away from her at all, IMO. I am sure I am fanboying a bit since I am still in the honeymoon phase of getting into her music, but she has taken so much unfair criticism over the years that I am fine with not giving a crap if she lip synched at the freaking Grammy's.
I know that in some cases, the band will play the song "live", meaning they play and sing all the notes, the morning of or the day before in that venue, and that's the version that will be used as a supplement. So it's them playing, live, but not in that moment, for various reasons (more for technical reasons outside the control of the band than actual performance).
Sidenote: I am bit stunned by a relative of mine who definitely identifies as a feminist, but is totally irrational about Taylor Swift (he rolls his eyes at any mention of her) and buys the "she has a team to write all of her songs for her" narrative. I would think he'd be embracing a female musician of this caliber being so successful; it's rather surprising. No clue where the "she doesn't write her own songs" narrative came from and why it started, but it's hilarious that some ignore the facts and still cling to that narrative.
I get not liking her music, I do. And sometimes the 'squad' thing gets a little much for me, but I'm at the point now where it's basically just hate. If that was, say, Alice Cooper or Dream Theater doing what she does, it'd be lauded as above and beyond, but it's her, so... My kid ordered a signed copy of Folklore, and it was only a couple bucks more (go to Myles Kennedy's site and see how much the signed versions are). In the package was the CD, and a sticker, a postcard and a handful of tissue paper stars. Doesn't sound like much but it was a professional package, done right, not cheap. She DOES have a significant hand in the writing and production of her material; almost all of her songs are written by her alone, or her and one or two collaborators. So what's different between that and having Desmond Child, or Robert John "Mutt" Lange (I love writing out his whole name for some reason!) participating in your album?
I think her biggest "problem" is that she's just so big that some things become untenable. Bruce is like that; when I was outside the theater for his Broadway show, he was dropped off by his car and he stopped to wave, and you could tell he wanted to talk or interact, but he just couldn't. The security formed a "box" around him and while I wasn't moving (I was in line for tickets and didn't want to lose my spot) you could sort of see the wave of people starting to migrate over to him, so he ducked inside. It's just not possible for performers of a certain "size" to do things the way a club-circuit act can. And once that happens, it's too hard to avoid that patina of "fake".