No, the list of UFP presidents in AotF is far from comprehensive, only listing 14 presidents in all. It's only a continuous list as far back as Amitra (2364-8), and possibly T'Pragh given that the Tzenkethi War (during which she was president) seems to have been in the early 2360s. But Thelian is the only president listed between Ra-ghoratreii in the 2290s and T'Pragh seven decades later.
I'm fairly certain that A Singular Destiny makes it clear that T'Pragh was the only President before Amitra. ASD makes it clear that Sonek Pran started advising Presidents under T'Pragh approximately 30 years before 2381, and that he advised every President between her and Zife. Since they only ever list T'Pragh when reciting his lists of Presidents, that means that T'Pragh was Amitra's predecessor. Since we know from AotF that no president has ever served more than three terms, that means we know that she had to have taken office in 2353, that Pran had to start advising her around that time, and that her last year in office was 2364 (requiring her to have served three terms).