While that may be a valid view from the perspective of a privacy warrior, it does not accurately reflect the ethics of journalism.

Wait, so the ethics of journalism require accepting TOS/EULAs? If that's the case, then quite a lot of very important investigative journalism in the past few decades is ruled invalid! (despite the touch of sarcasm, I'm also genuinely curious)

Journalism ethics do contemplate situations where otherwise unreportable news of crucial importance to the public should be published. Same for news about things that happen in private but are related to public figures. There can often be very serious consequences for the organization and reporter in these cases.

Neither applies here.

You're conflating whistleblowing with publishing conversations that are explicitly "off the record".

Don’t be ridiculous, journalistic ethics are just what’s convenient in the long run for journalists.

Well if you break the terms of service for a site, you shouldn't be surprised when you are permabanned. No more hip neighborhood social network for you.