Due to the world being inundated with lamp ban after lamp ban, I have been starting to have fears that some manufacturer part numbers of some lamps, ballasts and fixtures will have ZERO surviving working examples left in existence due to being scrapped, recycled, or burning out gradually and that have NEVER made it to anybody’s collections or have been discarded after the collector passed away. I am wondering if there are any discontinued lamp, ballast, and fixture part numbers that have ZERO surviving examples left in existence including having NO examples that even made it to collections like in the case with many part numbers for North American 1000W H34 mercury vapor ballasts. In these cases, I am specifically looking at lamps, ballasts, and fixtures that are even rarer than SO/H low pressure sodium lamps, medium pressure mercury vapor lamps, and rectified fluorescent lamps.

Decay and destruction awaits literally everything and everyone on earth, given enough time. Just like with steam engines, some things will just disappear. There are countless of those of which there's not a single example left.
And some things will just eventually wear out, or break, or something else might happen. How long will the metal-glass seals that keep the gas filling inside live? We're at about a century and counting, but who knows...

If you want to make sure that your collection will be preserved just a bit longer, then, together with your will/testament, include a list of your collection, which things are particularly historically valuable, and places where your family could bring them to, if they don't want to keep it themselves.

Finally, manufacturers have one goal and only one goal: making profit. They're not here to keep us happy. Philips/Signify's SOX lamps aren't caught out by any ban, but they quit making them anyway.
SON lamps also are still efficient enough to allow them here, afaik. Mercury containing ones are banned starting somewhere this decade, there are new ones available fully mercury free, yet city after city chooses to use LEDs anyway because apparently they're cheaper to run. So with declining demand, even those are gonna disappear sooner or later.

Grab what you can, enjoy it, and include some documentation for any family, so they know what's interesting and what not.

I think this question does not have any definite answer. Sometimes it takes tens if not hundreds of years to something that was thought lost to surface again. There are probably lots of old fixture models that have zero units existing anymore even without any bans just because no one had saved any. Yet it's possible that someone somewhere has one stored in a barn "full of junk" waiting to be discovered by hopefully someone who can appreciate it. 

there was a LOT of rare lamps that were market failures that we may not know existed at all that have come and gone and are now "rotting" in some warehouse somewhere
sulphur lamps come to mind and someone posted on here a vid of a scrapper with one scrapping it
QI lighting induction is another that is likely to drift off as most collectors look at it as a cool novelty but WANT VINTAGE Florescent OR Mercury

Agree, even quite recent lamps can vanish completely if product is a flop with relatively small production batch. Experimental or concept demos are also prone to disappear.

I wonder do lamp manufacturers have some sort of archive that contains samples of their products.

Back when LED was just coming to general lighting there was these liquid cooled e27 led lamps available. It looked really fancy but I always thought it was more of a gimmick than actual solution. I kind of regret not buying few back then. Apparently luquid cooling wasn't very good choice for retrofit lamps.

there was a LOT of rare lamps that were market failures that we may not know existed at all that have come and gone and are now "rotting" in some warehouse somewhere
sulphur lamps come to mind and someone posted on here a vid of a scrapper with one scrapping it
QI lighting induction is another that is likely to drift off as most collectors look at it as a cool novelty but WANT VINTAGE Florescent OR Mercury

I want induction lamps and ballasts. Problem is I can't find any locally (for sale) and don't want to pay eBay prices. Plenty of induction is still inside service around here surprisingly. It does a decent job.

@homebrew I never saw induction "retail" outside of finished fixtures and think you WILL have to go FLEEBAY
there are 2 streetlights outside my house small AELs and the one at the end of the road got "MURDERED" by the snow plow and they installed an induction jobby -Chinese thing that looked like a elongated M250R2 FCO used a donut style
I liked the light it put out but did NOT catch the utility guys swapping it out and it is NOW GONE )-:

It’s already happened in a way, take a lantern like GECs F2210 First Town from 1914 for instance, you can pretty much guarantee there’s none of them in existence anywhere?
But also we’re just talking about lamps and gear?, what about all the concrete columns that are no longer in existence?, they are also ‘lighting equipment’?, and outside of lighting collectors the loss of such things isn’t even a second consideration to anyone anywhere anyway! 

I want induction lamps and ballasts. Problem is I can't find any locally (for sale) and don't want to pay eBay prices. Plenty of induction is still inside service around here surprisingly. It does a decent job.

 Here 'ya go !  https://www.lighting-gallery.net/index.php?topic=15081.0

There is NO chance that I will ever again find any single lamp ballasts for 40W 2ft fluorescent tubes . After I disposed my spares ones in the late 90s there will not be any left in the wild, especially in Switzerland.

Fortunately all exotic wattages of ballast chokes can be easily emulated by running some standard easy to found ones in series/parallel combination.