"learned their lesson well now" - I don't think Russia has learned any lessons at all since Ukraine. Russia's sheer incompetence keeps getting worse and worse, as Prigozhin exposed on the inside. The war went from total failure to achieve any objectives for 5 years, to now 4 hour lines in Moscow to fill up your car at the gas station - i.e. Russia went from "failing to capture Kyiv in 3 days" to now "getting hit in the center of Moscow regularly".

Given the level of incompetence that Russia has demonstrated on both the political and military front, I highly doubt it could've turned anything around in Ukraine even if knew everything about 2014.