The stronger gatekeeping was in place for a long time and while it kept out trenders, it did not prevent troons from trooning exactly as they do today. Blanchard was a pioneer, after all, and also the one who documented the depths of AGP troonery in all its depravity. Yeah, this would probably stop some middle school girls from making a terrible mistake, but men who really, really want their laydee fetish to go public would hoist their pantyhose, grit their teeth, and soldier through the two years.
This cannot be said strongly or often enough: people who think they need their genitals shredded and resculpted are profoundly mentally ill. They are psychosexually disturbed, every bit as much as the guy who gets his jollies flashing grannies on the subway. They are abnormal and no amount of gatekeeping will help them, because at the end you're still opening the gate and allowing them to believe that their delusion is reality.