>>283129955
1. Oda wrote Carrot as the next Strawhat, fulfilling all of the "requirements" of one, but then Jump and/or his editors said he needs a character that's easier to sell to coomers and consoomers.
2. He then hastily replaced the well-written and established character of Carrot with a very media sexy character MADE for fan service, but one that also has zero substance. This is the Mary Sue known as Yamato.
3. Ultimately, having given up as the intended character of Carrot and the having grown tired of the shoddy replacement for her, Oda decided against having anyone join after Wano.
That's what he meant with it.