If you forget to salt the pasta water, there's no way of making it taste as if you had. And even if the salt dissolves well in the sauce, it won't permeate whatever chunky things there might be in the sauce as if you'd salted a lit bit every step of the way. But yeah, it'll be ok, even if it won't be as good as it would have been. (I know you didn't say it would be the same, just wanted to add).
Once i completely forgot the salt in my bread. It was disgustingly bland; like, I couldn't believe a teaspoon of salt would have such a massive effect.
But I actually salvaged it by putting salt on every slice of toast I made with that loaf.
Get the pancetta nice and crispy in the pan, add the garlic in the final minute before finishing. Add your pasta (2 minutes under al dente) fresh out of the water into the hot pan with as much carry over liquid as you can to deglaze, toss like your life depends on it (it does.), cut the heat, then add your mixed yolks, parm and fresh black pepper. Allow the carryover heat to thicken the sauce along with vigourous stirring to get the starches emulsified with the egg and cheese. Add more cracked pepper to your taste. Maybe a pinch of crushed chilis. Add pasta water and stir to reach your desired texture.
I think (hope) they are just describing this wrong, rather than adding bacon to boiling water at the beginning.
The sauce for carbonara is just some of the (salty) pasta water and egg yolk.
Cook the pasta until just before al dente, then mix the yolks and (fried) lardons in the pasta for the final minute or two of cooking. Add parmesan as you like.