It would butterfly away the Russian Civil War, but a Russian Civil War is still likely to occur. The 1905 revolution is going to happen, Russians coming into The First World War may still happen (Not because of a desire to restore prestige, but riding high off of a victory, plus the regular delusions of grandeur and balance of power). There are still huge social problems that a victory in the East won't wipe out, and may even be exaggerated (since troops able to be put into putting down the 1905 Revolution, there will be less pressure to accede to the demands of the revolutionaries).
People will still be poor, they'll still be hungry, education and infrastructure will still be broken, the aristocracy will still wield unchecked power, and the international situation will still be bleak because in spite of the victory Russia doesn't have their stuff together enough to be taken seriously anywhere West of the Urals.
As for the Navy... Well, it surviving would cause its own problems. The navy was pretty badly outdated, and the Russians would be better off scraping it and building new ships. IRL it was the buildup after the Russo-Japanese war that worried the British naval planers, not the fleet before. The loss of the sailors was... Well, it was unfortunate, but considering their performance they weren't irreplaceable either. The only thing really worth keeping from the 1904 Russian Navy was the officers.
I don't like being so hard on them, I think there's a lot of potential at this point, but Manchuria and Korea don't really get Russia anything. What they really need is governmental reform, and I don't know how they'd get that.