Has Anyone Undertaken Backing Up Every Known Shockwave game?

You could try, but it would be near impossible. There is simply too many Shockwave games to back all of them up. 

the only shockwave game i can recall off by heart is Rampage used to play it soooo much sad to hear the company is going hope we can save most of them

There are way too many Shockwave games, plus many of the games are just something you would put together in about an hour and call it a day. I doubt anyone would go looking for those kinds of games.

Ideally, maybe, but I think that with any engine that has a publicly available SDK you'll quickly find this to be an impossible task. Sorting it into categories of who published the game is the closest, most reasonable alternative and is much easier to catalog and organize. You can say "let's try and find all games from Miniclip" or "let's try and find all games from Shockwave.com" and it doesn't sound like too unreasonable a goal. Saying "let's back up all software made in this publicly available engine" is just shooting for the moon. Anyone who actually attempts this at any rate will discover it's not a viable approach.

In order to find lost media, it needs to be broken down into categories and then individual items. This is why the wiki is organized into categories - e.g. animations, films, video games... and then into articles about individual topics e.g. Cracks, Clockman... in order to back up as many Shockwave games as we can would involve breaking it down into categories first (by publisher is easiest) and then into individual games. Choose what you want to find first before going searching for it - saying you want all Shockwave games saved is just too much.

Yeah, no.

It's not worth the time, effort and money you'd need to crawl for these, especially since the actual loading of the DCR is usually behind some JavaScript to hide an ad or whatever. There may be loaders involved as well. Some websites require you to sign up to play games. However, even if you did have a spider crawling for these, I'd estimate somewhere around 75% of the resulting DCRs (or DIRs, or DXRs) won't work.

DCRs are often leech protected. Even when they aren't, they'll often require external resources or external casts. Let me tell you a story: one time I tried backing up the virtual Alberta Legislature, which is a Shockwave game. But it's so integrated into the site that you'd practically need to back up the entirety of LearnAlberta, which would take absolutely forever. Sometimes these games require external components, Xtras that are no longer available, servers that are no longer running. Some Shockwave games aren't facing the public web - they may install offline, such as what NickArcade or Cartoon Network Powerplay did. In these cases, the games take the form of EXE files. These would be far more difficult to crawl.

And I don't think you realize just the extent to which Shockwave was used. There must be tens of thousands, even hundred of thousands of games made using it, and even when it's discontinued it could still be used at any time. Why don't we back up every videogame ever made while we're at it? Every movie? Every animation? It's not like we wouldn't be doing that anyway if it were easy and affordable.

Can I ask how did you know that Shockwave is about to die in 2020? Just want to know. I am aware of that.