If you move to an empty seat to prevent WiFi signal strength triangulation, and assuming the cabin has no cameras, you didn't auth to the network with identifiable information, actually encrypt your Xray proxy connection (which OP didn't), and you have MAC randomization on, there's next to no way the airliner would be able (or even care) to identify that you did what was described in the article. Sure, they could use DPI and behavioral analysis to
detect you were misusing the network, but if they're doing that, they would just block this sort of "backdoor" from the get-go.
I'll echo the article's disclaimer:
This reply is intended solely for educational and research purposes. I affirm the strict adherence to all relevant regulations and service terms.