Originally Posted by
Fly Me To The Moon
The last time I checked in online for a HKG-TPE flight (this was the last sector of a ticket), I had to acknowledge that I did have an onward ticket before the OLCI could be completed. Of course, I actually did have an onward ticket (on EVA Air, so CX would not have had access to this booking, and I was not asked to enter any details).
This happened to me on an EVA Air flight from Paris to Taipei around 2017/18. Ground staff came to find me at the gate and, as I did not have evidence of such a ticket, asked me to sign a paper disclosure form acknowledging that if I was denied entrance to Taiwan I'd be liable for costs to the airline etc. The date next to the signature was printed with "19___" as the section to input the year, so perhaps those forms are fairly rarely used!