Also, I think it's more that the prequels are ignoring the functional text of the original; the mechanics that made it work so well to provoke fear and terror, namely, the unknown, and expanding more on the sexual/Freudian subtext and ironies of creation, with David being the centre crux.
How valid is this approach?
Well, given that Giger's aesthetic wasn't so much predicated on mystery or the unknown as it was on erotic transfiguration and psychosexuality, this is evoked with the revelation of an extraterrestrial rape and death machine moulded via an impotent android descending into madness as he utilises truly alien, Shoggoth-like bio-tech. That's far more nuanced than simply "man-made". David's an artificial alien himself in an organic/natural world, possessing the very thing mortals seek but cannot possess - immortality. Yet for all of David's superiority, he's uncannily identical to man sans the ability to reproduce or die. Thus, the phallic and vaginal designs and the predatory instinct are all an artistic, morbid mockery and transfiguration of human reproduction/mortality.
That is fundamentally Giger-esque to the core. Thus you could argue it understands Alien meta-textually insofar that it reflects Giger's sexual/Freudian themes, just not the mechanics of its effective horror/terror.
Heck, Covenant goes out of its way to subvert the original chestburster scene and present the organism as a thing of beauty, not something to be feared or reviled. Giger would've approved.