>>6741766They were basically mandatory in WWE after Sable became an active wrestler. And continued to be for AE and RA eras. The only way you did not have to get under the knife was if you worked in WCW where they were not mandatory and got signed by WWF. That's why Stacy Keibler and Molly Holly were able to keep their naturals.
Mickie James is a classic example. When she was in developmental she wondered why wasn't she being called up like many of the other women in there were. So eventually she asked Tommy Dreamer about it (who at the time number two person in Talent relations) on why she wasn't being called up. Tommy then very uncomfortably said that Mickie should look at what the women who were called up had that she did not have. And eventually Mickie proceeded to get breast implants and got called up very shortly after that.
Brie Bella also said when she innitially tried to go to WWE over the Diva search that she was also asked if she was willing to get breast implants since she had no boobs.
There are few other examples I could point out as well.