Your reasoning is not logic, a contract is a biding document, true, by ratify it means the go ahead is given, China has a bad track record with the J-11 license, plus add they copied without license the Su-33 and Su-27UB/MKK. Russia as a country has also people who see China not with the best of eyes. Sukhoi can not start building jets to get cancelled as the 200 J-11 license was, ratification is logic is you dig history.
Your line of reasoning is pretty not logic, the contract was signed, that is a fact Rostec is not making up things like most people say here, but the contract can be cancelled, it happens all the time, could it happen yes it can.
If you could be more realistic and see the contract was indeed signed but that this is not a bidding document to the end of the world, it is just a bidding document and both sides need to ratify it because Russia is not willing to spend money to build Su-35s and later for the Chinese to tell them well we do not want them, that is a thing any company will try to avoid.
Please show me a pic or video of the contract signing ceremony