Our OnePlus beta program is designed to test new features with a selection of our community. This particular feature was intended for HydrogenOS, our operating system for the China market. We will be updating our global OxygenOS beta to remove this feature.
The taobao guys invented some thing clever to walkaround the restriction, instead of blatant links, they invented hash code/token, which is called 淘口令, deep embedded in a wall of text, that special token, as appears to be match the RegExp /.*[¥¥《](.*?)[¥¥《].*/ from OP's result, can uniquely link to a taobao/tmall SKU. Since Wechat can not block arbitrary alphanumberic tokens, then ppl can share the crap they bought on taobao, via Wechat
But after all, there is always a catch, how does Oneplus ROM has anything to do with this?
Well, the clever-ass part is they will match certain strings from your clipboard, send the token to taobao API, and restore the original SKU links, so that the receiver can actually click the shit, this step is done outside Wechat, at ROM level. ROM will check for clipboard for certain type of token, they prompt in notification "will ya open this taobao/tmall link instead?".
That's it, that's why you will see strange URL requests going to Chinar IPs.