I think Nokia should learn a thing or two from brands like Motorola and Oneplus. They should really add some important gesture controls on top of stock Android.
I agree that the gesture controls in stock Android are very poor, not making good use of the touchscreen/proximity capabilities of modern smartphones. One gesture I miss a lot is swipe-right to go back a page in the browser, this was a slick feature on Nokia phones in the past.
Yup I think it will be no big deal for Nokia to add this feature whatsoever. You see small things like these tends to attract a big amount of users and this should also make life a little bit easy.