What will happen if the amount of NADP decreases in a light dependent reaction?

Photosystem 2 (PS2) breaks water to release oxygen (O2), protons (H+) and electrons (e-). 2 H+ and 2e- are carried over to the b6f complex by plastoquinol, where it undergoes redox reactions to generate a proton electrochemical gradient. Electrons from the b6f complex are transferred to Photosystem 1 by plastocyanin or cytochrome c6, which then generates NADPH from NADP. The proton gradient across the thylakoid membrane is discharged by the ATP synthase to make ATP. If NADP is low, the PS2 reaction is skipped and the electrons are shuttled back and forth between the b6f complex and PS1, generating only ATP. Hence, O2 levels should fall down.