I've got a Galaxy S7 that was purchased from Vodafone UK. It's receiving OTA updates in China no problem, and it doesn't have a Vodafone SIM in it.
This S7 only has one pre-installed Vodafone app "Start", that just says "Something is wrong. Please insert your Vodafone SIM card." when it's run. Also I'm pretty sure this phone was never locked when it was sold by Vodafone.