Now... you will be told that SI 'system integration' stock is completely and utterly different from 'boxed' stock. All I can tell you is the system I had built by OC last year with a zotac 2070 in it came with the zotac box which looked no different from the zotac amp 3080 box I have. I'm not suggesting anything dodgy is going on, just making an observation. We also know ScottiB gave some of his SI allocation to Gibbo for retail to help with the shortfall.
The situation is really quite surreal, both AMD and Nvidia keep launching card iterations that they can't supply in any meaningful fashion. I wonder how many 3090's have been bought in place of 3080's?
IIRC ScottieB has explained that.
GFX cards don't always get "special oem" packaging, especially if the volume they're turning out for that supply channel is low. Effectively it's not worth the manufacturers time to create separate packaging for it*, instead they divert some at the factory and put it in the SI supply chain.
I honestly can't see the higher end cards being sold in sufficient quantities even under normal conditions for most of the manufacturers to bother with making "oem" packaging. For lower end cards where tens or hundreds of thousands are being put into "gaming computers" to be assembled and sold in department stores, yes OEM packaing would make sense, but for cards were only a tiny fraction are going to specialist system builders...
I suspect OCUK is simply unusual in that they (from memory) supply most/all of the original packaging with some of their systems, most people buying a complete system wouldn't be bothered (or want) the likes of the GFX card, CPU or cooler boxes.
I suspect it's a bit like "retail vs OEM" hard drives but reversed - I've only ever had about 4 proper "retail boxed" hard drives** in nearly 30 years, as most "retail" hard drives are effectively identical to the OEM ones in terms of packaging (usually an antistatic bag plus whatever the retailer uses), it's just that a batch is registered as being for one supply chain (possibly with a different warranty) and sent out as such through the channel for system builders.
*Many manufacturers in all sorts of industries try to keep the number of distinct lines down, as it's pointlessly complicated to have one product but make two lots of packaging for it for very small volumes..
**Nice packaging, usually about the size of a DVD drive retail package, with a cable, screws, leaflet with installation instructions, and often a bit of software to clone your old one (and back in the day sometimes drive adaptors to let you fit the 3.5" drive in a 5.25" bay).