No, they didnt.
The suits are pre war, ordered by Sinclair to protect the workes from the cloud.
They are unobtainable because the workers when exposed couldnt escape as the seals corroded and because sif. They had to gut themselves out.
I assume they just mutated further trapped insde the suit and became what we see today, They remnind me of big daddies in bioshock.
But damn I would like one of those suits for my one character, preferabley the harvester because it has a hood.
The suits are pre-war, yes, and guess what? The Big Empty is a Pre-War location, silly!
Now, they might not have COME from there (The Big Empty), as they are supposedly Russian suits, but Elijah himself said that the suits, among other things like the Holorifle, the technology for the vending machines, and the Holograms can be found in the Big Empty.
And I'd rather trust him over you, because he's been there, you know?
At any rate, we wouldn't become stuck in it, but it would still be problematic because it is supposedly difficult to talk in the suits. I assume everything you say just sounds like Pyro from TF2. It would be amusing if you were incapable of talking to people while wearing the mask. They'd just say "Sorry, I can't make out what you're saying."
EDIT: Yes, I just confirmed Elijah does talk about the suits he says "Even the suits of those things stalking the villa" among the things that can be found in the Big Empty, and that this only scratches the surface of the stuff that's there. So yes, there are Hazmat suits like the Ghost Peoples' in the Big Empty.