Source was intel about the dates. Early processors not affected, now that may be before B0 production it was not stated. Speculation about the fab and hence the ? as I don't know what fab's are used to make them.
Can you please provide a link to something where Intel says that early processors aren't impacted? I'm not doubting that it exists, but it's something I haven't read.
Here's an article that has some interesting (if useless) info from intel quotes: Intel's Atom C2000 chips are bricking products – and it's not just Cisco hit
According to that, Intel declined to comment on when the impacted chips started and stopped shipping. However, they are also quoted on that article as stating: "Additionally, Intel will implement and validate a minor silicon fix in a new product stepping that resolves this issue." THAT statement indicates that it wasn't a case of some bad components mixed in with good, or a bad process at a single fab, etc. Rather, that statement seems to indicate that it was a design flaw (either logical or physical) that they can correct with a silicon fix in a new stepping (that doesn't seem to exist yet.) (If it was just a subset of chips with the issue, then they wouldn't need a silicon fix and new stepping...)
It does not seem clear of the bug is really a pure design issue and/or a material or material application issue. At least that's the way I interpretation it.
If the above linked/quoted material is accurate, it would be a design issue. (Keeping in mind that I'm including the choice of materials used as part of the overall design.)
Remember the c2000 has been produced since 2013, and it's been hinted at that it's only the chips that are reaching 18month now and will reason 18month soon that have the issue ?? What about the 2013 produced chips ?
I've seen many references to "18 months." NONE of them from Intel, and none of them are willing to directly connect 18 months with Intel. However, I think it's fair to look past the smokescreen and see the relationship. In that (likely valid) case, the stuff I've seen indicates that the issue is more likely to be a concern after 18 months. It doesn't indicate that it won't occur until then, and I'm sure there are plenty of 3+ year old chips in 24/7 use that never had an issue.
As for the 2013 chips that HAVE had the issue... I'm sure the majority of those owners were told that they were out of warranty... or in some cases, they got warranty replacements (if the warranty was long enough) without anyone officially relating it to this specific issue. Even now, with everything we think we know now, it STILL hasn't been officially related. Cisco, etc, have all been VERY careful in what they aren't saying.
I actually can't right now imagine what fix they could also implement on existing product, has anybody see what they add or do ?
That's an interesting question. I'd also love to know what the "platform level fix" could be that doesn't force a new motherboard revision, doesn't force any type of BIOS (or microcode) update, doesn't change the chip, and doesn't leave any clearly visible signs on an older board that supposedly has been "repaired."
At the very least, I expected to see some sign of hand SMT re-soldering on the replacement board. I don't see anything on either side. (Of course, I don't know what I'm looking for either, and there are a LOT of solder points on a motherboard!) I have to keep in mind that the "fix" might be as trivial as cutting a trace or replacing one of those extremely tiny components on the board. I might never see that even if I did know what to look for (and where to find it.)
Edit: Here's a page that supposedly answers your "what about 2013 chips?" question: Intel Atom chips have been dying for at least 18 months – only now is truth coming to light
(I say "supposedly" because none of the info in that article is directly confirmable.)