Before I left Reddit, I used a plugin through the api to replace all of my comments with random gibberish and then delete them. Part of this was because (mandatory) fuck spez. But more importantly, it was to protect the anonymity of my account. After years of posting, there is likely enough personal information shared to potentially connect my Reddit habits to my online identity. I wasn’t planning on using Reddit again in the future on that account, but I left it open in order to maintain some security control over the account. I’m not really sure what to do at this point because I still consider it a security vector that’s a bit concerning. There’s no way I can manually edit and delete all of my content with the snail’s-pace reddit UI, and I have no ability to assure that my content will remain unavailable or at least not publicly displayed.
While I don’t think that text analysis (TA) is going to replace those techniques that you mentioned, I do think that it is a threat to anonimity in the immediate future, because it’ll likely be used alongside those techniques to improve their accuracy and lower their overall costs.
The key here is machine “learning” lowering the TA fruit by quite a bit. People misattribute ML with almost supernatural abilities, but here it’s right at home, as it’s literally made to find correlations between sets of data. And, well, TA is basically that.
Another reason why I think that it’s a threat is because even a partial result is useful. TA doesn’t just identifies you; it profiles you. And even if not knowing exactly your name and address, info like age, sex, gender, location, social class, academic formation etc. is still useful for advertisers and similar.
(Besides the Federalist Papers and Robert Hanssen, another interesting example would be how the Unabomber was captured. It illustrates better how the analysis almost never relies on a single piece of info, but rather multiple pieces that are then glued together into a coherent profile.)
(Also sorry for nerding out about this, it’s just a topic that I happen to enjoy.)