Not trying to get into semantics because the nuances of BITOG are largely lost on my dinosaur brain but for historical purposes "GC"/German Castrol is the LL-01 0W-30 stuff that was made in Germany. It has had a unicorn-tears rabid cult-like tribologist following and even has its own FAQ on BITOG:
https://www.bobistheoilguy.com/forum...&Number=718643
Then at some point some people noticed the print on the 0W-30 bottles changed from "Made in Germany" --> "Made in Belgium" which prompted all sorts of conspiracy theories and virgin oil analyses. Around this same time the 0W-40 stuff comes out with LL-01 approval and "Made in Germany" on the bottle.
I used to pick up the old GC @ the local Pepboys but I don't even see it on their website anymore. Looks like advanceauto still has it.
I haven't actually run the "new" GC 0W-40 yet but I suspect it will be same as all the other LL-01 oils: i.e. completely fine based on routine UOAs (including M1 0W-40 LL-01, Motul x-cess 5W-40, BMW 5W-30, GC 0W-30.) And the fact that it's available for cheap in quantity at Wallyworld is a bonus (although I suspect other people have picked up on this because the shelf is always empty.) You can also get it for the equivalent price on Amazon (currently $26 - I've seen as low as $20.)