Everything in the world discriminates against some class of people. Taylor Swift is optimizing for "verified fans" - i.e., people who will actively share how big of fans they are. It's just good business, because she's developing a lifetime customer base. Someone will need to attend the "final tours" she gives when she's 60, 70, 80. Also, Taylor Swift fandom is one of the most mainstream fandoms I can think of - there's little risk of a severe reputational risk for admitting it.

I don't see how it's any better than discriminating against poor fans though via selling the tickets at market price.

It's better for the fans since they get more content with less money, with the tradeoff of some personal information.

Since the band and ticketing partner are not in the ad business and want to build long term, I expect that limited personal info to be much less likely abused than what the typical social network site does with even more sensitive data (yet, most people seem to agree trading those off to for free news of the Kardashians in their feed, so what do I know).

At the limit, any kind of price discrimination needs some type of information to execute, you can't subsidize completely anonymous fans because market forces will quickly close that loop and we are back to square 1. For example, a confidential association between my name and a record/stream purchase for the purpose of a substantial ticket discount in the future seems like a good compromise to me.