It's generally accepted that preventing the Bolshevik revolution would also save us from Fascism which was a backlash to the threat of communism. So, if in 1939, Italy, Russia, and Germany are under democratic governments or at least non fascist ones, what happens to Japan? I don't think they'll be trying to take over Asia if they have no allies elsewhere.
No. No Bolshevik revolution still leaves a Russia in chaos, and it throws the Far East out of whack. Japan could get more influence in Mongolia, no Bolshevik Revolution means no chance of the White Army in Mongolia, so instead of turning towards the Russians for protection from China, Outer Mongolia could look towards Japan.
Japan's attempt to take over East Asia was more really nasty mission that saw Japan go from trying to win the war against China and not necessarily conquer them, to trying to cut off their supply lines in Indochina to having to attack the U.S and East Asia or else risk running out of oil in two years. Japan did all of that without having A far enough POD could butterfly that away, not to mention there's no telling how the Taisho period will turn out in this timeline.
China is also going to be suffering from butterflies, at least with its relationship with Russia. The Soviets in OTL continued to use the Chinese Eastern Railway in Manchuria to the same degree the Tsarist government did, that is unfairly in their favor. How this new Russian government will react is another question entirely, if we can even settle on who can feasibly run it in the first place. Another thing is what does China look like without military aid from the White Emigres, or better yet does no Bolshevik revolution drastically impact or prevent the formation of the CCP? If so, China could be in a much stronger position it does not have to worry about the Communist subversion of its territory in Manchuria, Mongolia, or Xinjiang from the Soviets, or agitation from the CCP.