I'm pretty sure they wouldn't have "cloned" the actual GPU silicon, as that would be a hugely expensive undertaking, with minimal gains considering these are older, lower-end graphics cards. It seems unlikely that the chip was made in anything but an official factory (though I suppose it's possible they could have been made on unofficial runs after Nvidia ended production). And even on an "official" 550 Ti from a company like MSI, the processor would be worth very little at this point, since the card design is around 7 years old and no one is manufacturing them anymore.
And since graphics card manufacturers can typically choose what brand of memory chips and other components they want on a card, no "cloning" would be needed for that, as they should be free to use whatever cheap off-brand memory they want anyway, so long as it's compatible. It's possible that the board design or cooler could have been copied from another manufacturer, but again, reference designs are made available for that purpose.
These are more likely just GPUs that were built for the Chinese market, which have since become hard to sell due to them being a few generations old at this point, and not fast enough to meet the needs of most people in the market for a dedicated card. Rather than sit on old stock in a warehouse, someone likely decided to re-badge them as current-gen cards so they could extract some profit out of them.
Or maybe there was a stockpile of cards that were set aside as defective, that they decided to "refurbish" by simply tacking on some new branding without testing them or anything. : P