Are ex-CP-9 members present in CP-0? In the chapter 801 of One Piece, characters resembling Rob Lucci and Spandam were shown.

Are the former CP-9 members really in CP-0?
There is no evidence on what happened, but yes, they are. It's actually pretty clear if you see the chapter:


   


And also this is from the wiki:


   After the timeskip, Lucci reappeared as a member of CP-0. Lucci went to Dressrosa to recover evidence of the Donquixote Pirates smuggling operation only to find that they were already taken. Lucci suspected that the revolutionaries were responsible.