For a lot of people this "Gestalt" version of Nier, with the father character, is their original experience. We're also the people who bought, played, supported, and told others about this title back when the internet & gaming community at large couldn't care less about its existence. We are the reason Automata even exists; like it or not, without father Nier, this franchise would be dead in the water. This version of Nier absolutely deserves preservation.
I've played the original Replicant version of Nier; and, while it is still the same game at its core, it's fundamentally different with the brother character protagonist. Myself and many others identify more with the father character; we find that it suits the story better, and Jamieson Price's performance as father Nier is exceptional. The Replicant remaster also changed the way the characters look, retconning Kaine's appearance into an inferior-looking 2B look-alike, ruining her characterization as a tough, sexy badass by giving her an unfitting doll-like face, turning her into another unimaginative waifu-bait character rather than preserving her original unique juxtaposition of being somewhat gruff-looking yet alluring and sexy by the way of her dress. The people responsible for Kaine's visual redesign in the remaster lack a fundamental understanding of what originally made the character appealing and amass so many fans.
I'm ultimately fine with various versions of Nier existing—the franchise has been this way since its very inception—and people can and should play their preferred version without judgement. But this franchise simply wouldn't exist as it is today without this version of Nier; it absolutely fits GOG's mission and deserves to be preserved in its original form. I hope someday we can see this version of Nier get the respect and recognition that it deserves for kick-starting this franchise in the west, rather than having it be doomed to PS3 and Xbox 360 oblivion for all time.