But most of them did.

i think their good to get boop jops on som of them

I KNOW SOME didn't.

Through the early 1990s there were only a few, and until the late '90s Playboy denied that ANY Playmates had boob jobs. By that time they couldn't make that claim, as many Playmates began acknowledging, if not celebrating, their enhancements (among them, Jenny McCarthy, Anna Nicole Smith, and Pamela Anderson (post PMOM)).
More recently Playboy is known to encourage it's less buxom playmate candidates to have breast enhancement so they will have the best chances of moving up from just modeling to become a PMOM.