Sure.
In one scenario, Oda did it so Sanji would wake up being treated by Osome, and the "sanji hitting her" would be dealt with.
Maybe he does wake up with Black Hair.
Or maybe he just got exhausted from almost being impaled by King+being hit by Black Maria without defending with Haki+running around Onigashima like a headless chicken+having to fight both King and Queen for a while+suffering a complete skeleton morph+fighting Queen for 20 chapters+running again around Onigashima but this time with a heavy emotional stress load+tanking lots of Queen attacks+having to move at an extremely high speed for a while+finishing off Queen.
No senzu bean for him, btw.