I mean, unless the hackers logged in, left the 2FA prompt up and then a user completed the 2FA exchange, but that would be a foolish thing to do anyway...
edit: thanks for the answers; makes sense!
How is it easier to break Teamviewer's 2FA implementation than PayPals?
I (think I) now understand why "and my PayPal has 2FA enabled" points to TV being compromised -- If the PayPal account has 2FA active, and they were still "hacked", then it points to an existing session being hijacked. And a probable cause of that would be a compromised TV session.
So it's not necessarily an indication that TV's 2FA was compromised, but rather that TV was compromised in general, allowing the hacker to hijack TV sessions. (I'm imagining that the TV 2FA happens on their central server, and not on the actual server daemon running on the target remote machine... so if the central server was compromised...)
edit: Obviously this is entirely speculative, I don't know any of what's going down, but it resolves my initial curiosity.
Your paypal account getting hacked isn't a Big Deal, you aren't going to lose any money over it. In fact, managing that is paypals entire business model.