I don’t think Loki will be in the main cast since we are already one arc into the final saga. That last spot has to be left for Vivi ATP.

I never understood people thinking yamato would join the crew after Jinbe officially joined in onigashima. Yamato would disrupt the power dynamics of the straw hats too much and would possibly make arcs hard to write around.

I def see the giant pirates making a comeback since this chapter mentioned their backstory as the most terrifying force on the seas even above the world govt.