Firstly, the new Mace. With the exception of Starkiller, who was a special case, every other prerequisite legendary toon has needed other toons about their rise to who they are now. JKCK needs Merrin, Cal, Cere and Saw. GI needs the Inquisitors. Jar Jar needs the Gungans. But now Master Mace needs CX-2, someone who he never interacted with. Appo was 501st. He's probably going to need the disguised clone as well, despite being dead before the disguised clones made their appearance.
The upcoming raid, too. At least with the Naboo raid, they were old toons that most people already had. Granted, Appo was present during Order 66, so he and the disguised clone make perfect sense. But CX-2 again? Being an outlier once more. This is what I mean by CG wanting you to spend tons of money.
By the time F2P players get these guys geared up and Reliced, the good rewards have been moved to some new event. The new raid shouldn't require ALL of these new characters. Mace shouldn't need CX-2. Believe me when I say CG are implementing game designs that make it much harder to want to be F2P.