But it looks like it's in all sorts of places - how do you think the language model ended up thinking that was a good autocomplete?

There appears to be a name on a YouTube channel too that doesn't even need any additional steps (ie the jumping into repos and then licence files you mention above)

Putting that aside, why is this such a concern? it's just a label. It would be another thing if you had something more meaningful being revealed (eg current physical address) but username / real name alone is generally not that big a deal and it's plausibly deniable (ie there could be plenty of other username / real name pairings that are valid)

Anyway, this comes across rather like the Streisand Effect