Hi!
But Korea will not become independent after WW1 even in the worst case scenario for Japan. Korea would be given to Russia or another nation (depending on which side Japan lost), but definitely not independence for Korea.
Why do you think many former Entente nations are so deep in WW1 mythpeddling? They were supreme, conniving self-censored in Versailles and Trianon and know it today. Hence the propaganda to feel better about themselves.
OTL pre-1904 Russian aims in Korea were two things:
1. a neutral, preferably pro-Russian government in control.
2. a few major harbours to always be kept open for Russian warships.
I do not expect these objectives to change much TTL, unless Russia finds a compelling reason to keep another ethnic minority under its roof.
Furthermore, various states occupied by the Central Powers at which they were winning(i.e. Baltic States, Poland) were retrieved and given independence. All these states were, note, previously Russian territories. The only example that I can think of where a territory rightfully someone else's but given to another was German Tsingtao, and that occurred because Japan joined the war earlier than China, along with having more participation.
I hope the things I have stated above do not sound like mythpeddling, because then I would be completely unfounded in my assertion.