Two sides on this one.
On one hand, it would be fucking nice for some platforms to be held liable whenever doxxing happens. Because I can tell you, nothing good ever comes out of being doxxed. It would also mean that, people like Spez would have to run around the clock, sanitizing Reddit because he knows a lot of shit happens on that platform every day. In this sense, I would love Section 230 to be sunsetted.
The other hand, if this is going to be projected as a means to illegalize the expression against politicians and the US government, they're now stepping on a clear violation of the first amendment. Onslaught of lawsuits and contests incoming that would give politicians headaches.