This is standard Google behavior. Logging into Google on any new device always asks me to confirm it on one of the other devices that are logged in (i.e. phones, tablets). Suppose it's some kind of 2FA.
I understand the security concept of it. Luckily my trip was short. As I also use wechat to communicate with some Chinese friends, my experience was different. First it send me an OTP on the new phone, then asked for two friends to send a number to the phone. Luckily I had the phone number of one and I managed to restore and to be honest having humans in the pipeline was a plus. Negative this had to be done over 5 minutes otherwise you back to square one.
