The big problem here was that the company lied about it, because sharing mental health data for advertising purposes is totally legal in the U.S., as I wrote about last month:
"We’ve confirmed that Irwin has access to user DMs as part of her position. Given the way the company has handled the Twitter Files, multiple former employees told us that DMs are no longer secure, and have discouraged us from using them for any remotely sensitive communication."
"Tonight’s suspension of the Twitter accounts of a number of prominent journalists, including The New York Times’s Ryan Mac, is questionable and unfortunate. Neither The Times nor Ryan have received any explanation about why this occurred. We hope that all of the journalists’ accounts are reinstated and that Twitter provides a satisfying explanation for this action."