It's not that - any lefty journalist would be perfectly on-board with saying "trans women are women". I think it's a combination of John not quiiiiite wanting to burn his trump card and publicly disavow being trans, and a lot of alternative phrasings having uncomfortable implications.
Simply saying "She is not transgender" was probably shot down by John.
Something like "A previous version of this article said she is transgender when in fact she is a woman" would be like implying trans women
aren't true and honest women *clutches pearls*
Just saying something like "We retract this statement" would leave the readers asking why, and possibly finding inconvenient truths online.
Disappearing the comment without notification would be shot down by the editors, as well as making the paper look like Fake News when people pull out the archives.
So, we ended up with the silly "identifies as a woman" phrasing as the only
canidate left standing that sufficiently papers over John's lie and doesn't trample progressive pieties.
Now imagine all this being hashed out in FRANTIC ALL CAPS DMS from Wu Campaign HQ
EDIT: you know, there's one more dodge they could have used, but didn't think of.
"A previous version of this article referred to 'transgender video game designer Brianna Wu'. This should have read 'Brianna Wu, designer of transgender video games'. We apologize for any confusion this caused."