Don't believe everything you read.
I also used to believe to let Hormones do their full effect until BA. But you will never know WHEN the hormones effect is maxed.
Everyone has different results based on the amount of Hormones they take and their genetic makeup.
I asked my BA Surgeon who has over 25 years experience with Transgender people and he's never heard of such thing.
My Endo was the same way.
It's up to you how long you want to wait.
You have to be your own judge.
I decided to get BA at my 21 month mark on HRT and it was the best decision I ever made. I am a 42 Full C with 385CC per side and am told by Family and Friends if they didn't know me, they'd thought they were Boobs of a 25 year old.
The Surgery was flawless and I had ZERO pain or discomfort after. Just had to get used to the extra weight.

I almost did the "Wait forever and see what happens" thing until I just asked around more and watched my growth prior to BA.
To each their own.