"Hi! Your account may be hacked. To mitigate it, you need to log in."
I didn't even know I had a Twitter account, and so 2FA certainly not. So as a person who never uses Twitter, to get a mail like this is a conundrum. Better log in and change that password or whatever, right? So suddenly someone who never used twitter, or apparently did sign up once some long time ago, is logging in for the first time in ages.
Corporate: "See, users are coming back to our platform!"
Then again, it could be a phishing attempt, too, but either case is un-good. Someone tried to log in multiple times over 6 hour intervals and over 2 days, so obv hacker, but still.