Oda will give CP0 some ability that is really hax, but not necessarily that strong, in order for them to pose a threat. Basically what every minor villain has (Foxy, Caesar, etc)
The most likely choice will be that it will be some form of super speed. Advanced Soru combined with Zoan awakening.
This would allow them to avoid direct combat with Luffy or Zoro and create tension by targeting Robin, Bonney, and Vegapunk, who would be helpless against such a technique(Robin could nab Cavendish, but that won’t work on an experienced haki user that can negate DFs)