These vehicles were designed by GM to be 'Hub Centric
' in supporting the wheel.
You risk having the wheel mounted slightly off-center, but that is not as big an issue on most cars as the lug strength is.
Use of just the lugs to support and center the wheel puts lots of extra load on the lugs they were not designed to take.
It is very common to find vehicles with non-hub-centric wheel systems with broken of missing studs/lugs. I see this all the time at local car shows
This is not to say that use of those wheels AND the proper hub-center adapter would be more or less strong as a GM sourced wheel.
Or, you could consider upgrading the factory studs to a larger and/or stronger aftermarket sourced system to give you piece of mind non-hub-centric wheels will stay where you put them ...
Oh, when I was looking at some 'Returns'
they had for sale at the Reno store a few weeks back I did notice the "Made in China" stickers on the back of the rim
The 'name' rims in the rack didn't have those ...