The fingers in 267 look exactly like when he spat them out in 263, and they also resemble when he concentrated all of his fingers that were in Yuji to take over Megumi's body. Also, the fingers shouldn't be destructible. And Gege making him spit them out just to destroy them later would be pointless

I think that he may have prepared some plan B as soon as he realized that his defeat would be due to him losing the body. There's Tengen too, we've no idea about what happened to her. And Sukuna's last words telling that he shouldn't be underestimated because he's a "curse"...