well I would find it hard to believe they would make such a move before the olympics. Plus how many ships carrying chinese troops would be sunk before they left the port? We have quite a few attack subs that have too much time on thier hands.
Pragmatically, China would not care whether anyone came to the Olympics or not. The main concern would be whether anything would be left of their military after they attacked Taiwan. The attack, successful or not, could put China out of business for decades. Their incoherent and confusing history would add yet another incoherent and confusing chapter as China collapsed from within to eventually two or four different countries, none of them able to rule Taiwan.