The weird thing is, with all the screentime Holo Sid/Palp had, it seems like a no-brainer in the regular line. And Plo and Aayla, who only briefly appeared as holograms, would be better suited for exclusives of some type.
But then again, Holo Palp is a big enough character to justify the hassle of an exclusive, while Exclusive Holo Aayla and Plo would probably wither and die on the pegs.