There's just too many guns pointed to most of those nations for them to contemplate aiding a crazy war of aggression against China.It's not a statement. It is a provocation exercise. The provocation is to analyze if really all the countries in the region or most of them will adopt neutrality between a war between the USA and China, I can accept the optimistic version that there will be neutrality, but I do not share this optimism because I see clear intentions and directions that this may not really be true.
If you stay neutral or help China tacitly, its not like US has the ability to start attacking everyone. On the flip side, China's active defense doctrine means they will hit your infrastructure with at least some drones and possibly heavier munitions too. Countries like Indonesia or Thailand have very limited air defense, navy and air force.
Even actual states that are united into USA such as SK or Japan will not necessarily help. Especially SK that faces direct bombardment and land invasion from the 38th parallel.
A realistic estimate would be that regional US puppets act similar way as Belarus has done in the Ukraine war. Optimistic estimate would be that SK or even Japan declares open neutrality.
Saying Indonesia will help an American invasion is US nationalist cope pipe dream levels of belief. Its like those Russians who think Poland will help them by invading Ukraine from the other side lmao.