I couldn't care less about preservation of every damn 40-50 year old game that most people already forgot about and half the people who played it back then already are already dead. Only the most relevant and influential games from the 70s and 80s are worth a damn nowadays, proven even more by how most people reacted to all of those irrelevant NES games that Nintendo added to NSO that most people never heard of. Nobody cares about those games.
Most of those 670 lost games no one would have ever played again or cared about anyway if some archive still had a copy.

Throwing out game code is stupid obviously, since then publishers can't just rerelease games like SE is doing right now with many of their 90s games. But it's in no way the publisher's obligation to preserve their games. It's just smarter to do that, because it can make them money decades down the line.
I don't get the obsession with playing original versions of certain games if remasters and remakes are almost always better in most ways. Nostalgia plays a big role but sometimes it's just unreasonable.

That all said, Nintendo is already is preserving all of their games and most of them might end up seeing the light of day eventually... or not.

Games are an art form and we usually care about preserving art. Museums exist with that goal. Now, not everyone cares about old art, but overall it is an important part of our cultural history.

We don't typically preserve every drawing ever made in art...  just the influential pieces....  I agree that preserving key influential games is cool, but as somebody else stated 95% of old games are meh and don't need to be treated as Starry Night.  And the influential games are well preserved and have been released many times over on many systems.  

You have no idea.

An entire batch of historians is freaking out whenever a game is becoming unplayable for whatever reason and the code isn't properly preserved. They are fighting for years to force Video game companies to safeguard the code for future generations, with little avail so far.

They are also behind the archive.org DOS games page where you can download and play old DOS games in your browser in an effort to preserve DOS games:

https://archive.org/details/softwarelibrary_msdos_games

Like I said, I don't personally get that.  And I staunchly believe 'forcing' a company to preserve code is wrong.  It is their code.  They can do whatever they want with the code.  Nintendo (or anybody else) doesn't owe their IP to others.  People feel far too entitled.  My wife is an artist...  she can destroy her art anytime she wants, it is her property.  We don't own other people's property because reasons.    

I think we should hold until details are released before celebrating to much or expecting others to take note.

Some very influential games have been lost over time, especially those from the 1980's and early 1990's. Also many MMOs are lost forever now, even some who ran for quite some time and were pretty influential.

What is influental and what not is often subjective. And even then, some clearly influental games are lost.

See for instance Neverwinter Nights from AOL, the first *graphical* online multiplayer RPG (there were already text-based MUDs).
https://en.wikipedia.org/wiki/Neverwinter_Nights_(1991_video_game)

Influental also isn't always successful, it is much more likely that successful games are preserved.

And also for cultural historical reasons games that aren't influental are still interesting. Take the Satellaview games. Obviously that wasn't influental, as no one did something like that after. But it is an important chapter of gaming history, just because it is so unique.

We are on a digital era. The only way to lose a game nowadays is if the publisher absolutely wants to destroy it. Every person who have downloaded a game is preserving it. 

That's said, some games are impossible to be fully preserved. How will we play League of Legends once the servers are shut down? The answer is, we simply won't and there is absolutely no reason to freak out about it 

Think about other forms of arts that degrade with time, like architecture. Older buildings, they degrade with time and is simply impossible to keep every single one of them identical to what they used to be. What is reasonable is to select a few of them and... I don't know the word in English, in Portuguese is "tombar" which means acknowledge the historical, artistic and cultural relevance of some piece or property and turn them into a public property, which gave the state responsibility over its maintenance  

In cultural areas of cities some buildings frontage can't be remodeled because of laws. 

Thats exactly what should happen with games. We need to select a few of them and turn them public property when recognized their historical and cultural value

This, however, is so far ahead in future that is totally pointless to even discuss right now. It's something to think about in maybe 100 years,  not now. Games that are likely to become public property are the ones that are popular enough to have several copies and backups distributed, preserving those will be a non issue. That's not counting the possibility of some IPs being to successful that still no reason for them to become public, have any of early Disney movies disappeared so far? 

Regarding your last paragraph.. This probably explains why Nintendo's rereleases, remasters and remakes are so good. All devs should do this imo *Cough-SquareEnix-cough* https://screenrant.com/final-fantasy-source-code-lost-no-leaks-square/