Is Nov 1 1950 when they tried for real?
It's a pivotal time
If it succeeds, PR nationalists are subject to a big crackdown.
This could also seriously affect the conduct of the Korean War in the short-term.
(1) Vice President Barkley might, as President, take the stance that he is at least considering allowing MacArthur to take various measures against the Chinese.
and, independently of that
(2) If and when armistice talks happen, Barkley may not make a sticking point out of protecting enemy soldiers who want to defect. He might figure no Chinaman, even one who hates communists, is worth the blood of another American GI. [I'm not suggesting he would cut and run from Korea, but if the Chinese insist on full exchange of prisoners, he might say, "what the hell, why not"
and,
(3) Truman was worried that accepting an armistice on the terms Eisenhower later did would be politically risky. Barkley, as an oldster not plausibly up for reelection, might decide to take a status quo armistice earlier and take the political limps personally well before the 1952 election.