No two people will get the same response from the same macro ratios, it's all going to be up to your genetics, how you train, and what you choose to eat for meeting those macros that will decide where you're going to end up. It doesn't pay to obsess about various macronutrient ratios unless you are going to try them and see how you fare on them - I've gained and gotten up to 283 lbs. and strong on lower protein (about 15% of total caloric intake), but I also got fat as hell at the same time. I've gotten down closer to single-digit bodyfat at 225 lbs. by putting protein @ 35-40% of my total calories and have managed to exchange about 8 lbs. of fat for about 6 lbs. of muscle without any real "dieting" since the start of the year. To me, this shows that my body prefers higher protein and far fewer carbohydrates, but that's just MY system, and won't be the same for everyone else.
I envy those people who can eat 60-70% of their calories from carbohydrates and stay lean, but it won't work for me. Tried it off and on, ends up with me making strength and size gains, but plenty of fat along for the ride as well.
Basically, you MAY be able to do well for gains on lower protein so long as the calories are still above what you expend every day, but there's no guarantee. You may be better off with more protein, or, it may make little difference - the bodybuilding world would be much better off if the actual science were left as it is and people didn't constantly try to market their theories as universal across all people. It only adds to too much overthinking, it gets confusing, and people end up spending too much time having faith that a big change in macros will suddenly give them something they've always hoped for. Sure, it may well be that a standard bodybuilding macro plan works well for MOST people, but that doesn't mean it works best for everyone, trial-and-error is the only way to know what works best for you.
Best solution? Try the lower protein approach for a while, see how it goes as a 3-month test (just don't make it a 3-year run like I did), if you're not happy with the results, then ditch it and change things up. If you like it, keep at it until you're no longer satisfied with what it gives, and then change things up. But, if you don't try it, you'll never know how well you'll fare on it, and crazier stuff has happened as far as what people have gotten for doing something different in the face of bodybuilding "fact" that's often loosely based on actual facts and have been been twisted to meet someone's hypothesis just so they can attach their name to a book or article.