I think it's different. Think of it this way, you might have a public social media presence, but if someone made an API to search your particular social media presence it feels a bit weirder than it just being publicly available. Search engines are course enough that the chances are like 0.000001% one of my comments would ever come up unless you were specifically looking for it, but the idea that now an AI can be queried to be like "what did this guy write on Jan 1 2013 when he was possibly drunk" feels, well, icky.

I think we're all aware that what we say on the internet lasts forever, and frankly that kind of sucks for pretty much everyone that's ever put their foot in their mouth (so: everyone). But, at least things fade. Putting an AI on it though seems really extra, especially since there isn't anything of particular value here (it's not like this is a Q/A site or something where indexing peoples comments is useful)

Personally when I write things on this site it's to test my ideas or for the hedonic enjoyment of arguing on the internet, but I also gain no value from anyone reading my comments past their sell-by date.