I strongly suspect that stores operated by overseas companies, as well as China-based merchants with foreign-related business, may now all have this permission enabled. Today I discovered that the WeChat Mini Program for Taiwanese milk tea brand KOI also accepts payment with US credit cards (takeout is supported). It is also expected to have enabled in-store QR code payment as well (KOI scans your WeChat QR code).
If you want to learn more about WeChat offline payments, online payments, Mini Programs, QR code payments, and detailed how-to guidance, please see what may be the most comprehensive guide on the entire internet to using US credit cards with WeChat: