You described Chinese people organizing and attending an open technical conference with permission, and offer the unproven statement that several speakers would have refused to speak if they had known just how "Chinese" it was going to be ahead of time.

I'm not sure how those speakers couldn't just cancel, sure they'd lose any speaking fees but I've never heard of lock-in speaking contracts for conferences. Or if they care so much they could just modify their speeches to not supply anything of value. Or perhaps they should have done their homework ahead of time.

In any case I'd hardly call it a "nefarious trick" regardless of who was doing it. I'm hesitant to throw out "racist", but you seem to be leaning that way...