Either the Chinese miners plus dev would start a new fork (with majority hashpower) or they would suffer loss and humiliation as their pull requests were rejected.
Reality check: The Chinese miners (most miners, actually) are in it for the money. Majority of hashpower isn't worth sh*t if they are mining a worthless coin. If you are humiliated by a rejected pull request, you should find something else to do. Seriously.
Yes, miners are mostly profit oriented, from money point of view, they would take the lowest risk approach, either never implement any change since a full block will raise their fee income, or a small change to make sure nothing changes dramatically for their business model
1. Keep the size at 1MB forever, no scaling allowed
2. Higher fee income for miners
3. Miners expand mining operation
4. More competition cause higher difficulty
5. Investors previously get coin from mining have to buy from open market
6. Price rally and attract more users
7. go to 2
At meantime all the small transaction go off-chain, there will be thousands of off-chain services popping up since only those who move more than 10 coins at once can afford high transaction fee like 0.1 bitcoin per transaction (That's 200 btc per block, miners going crazy exactly like ASIC frenzy

)