Originally Posted by
moondog
1. I almost never book seats beforehand unless doing OLCI
2. Anybody can transit in China without visas; transit visas still exist, but are very rare these days
3. VOA is kind of complicated, but in many cases you need an authorisation letter from the entry exit bureau in order to avail of it
Sorry mate, but when was the last time you actually flew as a tourist transiting flights in china, especially in Xiamen?
I can speak from experience in October 2018 which is fairly recent.
I flew with the same airline OP has booked via the same airport. Unless you have any evidence for your claims I have to rate your comment as useless and actually bad advise for OP.