Yes but try to imagine Luffy fighting Kaido pre TS lol, it would have felt jarring.
If we were always going to have to wait until the NW to fight Yonko, then Oda would have always had to fill out earlier plot with other pirates.
I think its cool the Shichibukai were diverse. Only 3 were direct villains. 1 is a strawhat. 1 is a direct ally (Boa). 1 is an indirect ally (Kuma). And one is an endgame goal for Zoro. The replacements either became Yonko, or are Luffy's allies (Law). The only exception is Weevil currently, to which we dont know what the point of his character is